README.md

Pytago is a source-to-source transpiler that converts some Python into human-readable Go.

• Try out the web demo

Installation and usage

There are two "officially" supported ways to use Pytago:

1. A web application you can run via docker
2. A locally-installed command-line tool

Web application

Prerequisites

• Docker

Installation and Usage

Running pre-built container

docker run -p 8080:8080 -e PORT=8080 -it nottheswimmer/pytago

Building from source (Alternative)

git clone https://github.com/nottheswimmer/pytago/
cd pytago
docker build -t pytago .
docker run -p 8080:8080 -e PORT=8080 -it pytago

Usage

# Open the user interface
open http://127.0.0.1:8080/

# API
curl --request POST 'http://127.0.0.1:8080/' \
  --header 'Content-Type: application/json'  \
  --data-raw '{"py": "print(\"Hello World\")"}'

Local command-line application

Prerequisites

• Go 1.18.x
• Python 3.10.x
  • No, it will not work on 3.9 due to the (heavy) usage of match statements.
• Required libraries for post-processing:

  go install golang.org/x/tools/cmd/goimports@latest
  go install mvdan.cc/gofumpt@latest
  go install github.com/segmentio/golines@latest
  export PATH="$PATH:$HOME/go/bin"
  

Installation

via pip

pip install pytago

via setup.py (dev)

git clone https://github.com/nottheswimmer/pytago/
cd pytago
pip install -e .

via setup.py

git clone https://github.com/nottheswimmer/pytago/
cd pytago
pip install .

Usage

usage: pytago [-h] [-o OUTFILE] INFILE

positional arguments:
  INFILE                read python code from INFILE

options:
  -h, --help            show this help message and exit
  -o OUTFILE, --out OUTFILE
                        write go code to OUTFILE

Examples

All examples presented here are used as tests for the program.

listappend

Python	Go
def main(): a = [1, 2, 3] a.append(4) print(a) if __name__ == '__main__': main()	package main import "fmt" func main() { a := []int{1, 2, 3} a = append(a, 4) fmt.Println(a) }

abs

Python	Go
def main(): print(abs(-6)) print(abs(3)) if __name__ == '__main__': main()	package main import ( "fmt" "math" ) func main() { fmt.Println(math.Abs(-6)) fmt.Println(math.Abs(3)) }

helloworld

Python	Go
def main(): print("hello world") if __name__ == '__main__': main()	package main import "fmt" func main() { fmt.Println("hello world") }

input

Python

Go

def main(): print("Hi, what's your name?") name = input("Name: ") print("Hi", name, "how old are you?") age = int(input("Age: ")) print("Describe yourself in one sentence:") description = input() print("So your name is", name, "and you are", age, "years old, and your description is", '"' + description + '"') if __name__ == '__main__': main()

package main import ( "bufio" "fmt" "os" "strconv" "strings" ) func main() { fmt.Println("Hi, what's your name?") name := func(msg string) string { fmt.Print(msg) text, _ := bufio.NewReader(os.Stdin).ReadString('\n') return strings.ReplaceAll(text, "\n", "") }("Name: ") fmt.Println("Hi", name, "how old are you?") age := func() int { i, err := strconv.ParseInt(func(msg string) string { fmt.Print(msg) text, _ := bufio.NewReader(os.Stdin).ReadString('\n') return strings.ReplaceAll(text, "\n", "") }("Age: "), 10, 64) if err != nil { panic(err) } return int(i) }() fmt.Println("Describe yourself in one sentence:") description := func() string { text, _ := bufio.NewReader(os.Stdin).ReadString('\n') return strings.ReplaceAll(text, "\n", "") }() fmt.Println( "So your name is", name, "and you are", age, "years old, and your description is", "\""+description+"\"", ) }

randomness

Python

Go

import random def main(): print(random.random()) print(random.randrange(9000, 10000)) print(random.randint(9000, 10000)) items = ["Hello", 3, "Potato", "Cake"] print(random.choice(items)) random.shuffle(items) print(items) u = random.uniform(200, 500) print(u) if random.random() > 0.5: print("50/50") names = ['Kitchen', 'Animal', 'State', 'Tasty', 'Big', 'City', 'Fish', 'Pizza', 'Goat', 'Salty', 'Sandwich', 'Lazy', 'Fun'] company_type = ['LLC', 'Inc', 'Company', 'Corporation'] company_cuisine = ['Pizza', 'Bar Food', 'Fast Food', 'Italian', 'Mexican', 'American', 'Sushi Bar', 'Vegetarian'] for x in range(1, 501): business = { 'name': names[random.randint(0, (len(names) - 1))] + ' ' + names[ random.randint(0, (len(names) - 1))] + ' ' + company_type[random.randint(0, (len(company_type) - 1))], 'rating': random.randint(1, 5), 'cuisine': company_cuisine[random.randint(0, (len(company_cuisine) - 1))] } print(business) if __name__ == '__main__': main()

package main import ( "fmt" "math/rand" "time" ) func init() { rand.Seed(time.Now().UnixNano()) } func main() { fmt.Println(rand.Float64()) fmt.Println(func(start int, stop int) int { n := stop - start return rand.Intn(n) + start }(9000, 10000)) fmt.Println(func(start int, stop int) int { n := stop - start return rand.Intn(n) + start }(9000, 10000+1)) items := []interface{}{"Hello", 3, "Potato", "Cake"} fmt.Println(items[rand.Intn(len(items))]) rand.Shuffle(len(items), func(i int, j int) { items[i], items[j] = items[j], items[i] }) fmt.Println(items) u := func(a float64, b float64) float64 { return rand.Float64()*(b-a) + a }(200, 500) fmt.Println(u) if rand.Float64() > 0.5 { fmt.Println("50/50") } names := []string{ "Kitchen", "Animal", "State", "Tasty", "Big", "City", "Fish", "Pizza", "Goat", "Salty", "Sandwich", "Lazy", "Fun", } company_type := []string{"LLC", "Inc", "Company", "Corporation"} company_cuisine := []string{ "Pizza", "Bar Food", "Fast Food", "Italian", "Mexican", "American", "Sushi Bar", "Vegetarian", } for x := 1; x < 501; x++ { business := map[string]interface{}{"name": names[func(start int, stop int) int { n := stop - start return rand.Intn(n) + start }(0, len(names)-1+1)] + " " + names[func(start int, stop int) int { n := stop - start return rand.Intn(n) + start }(0, len(names)-1+1)] + " " + company_type[func(start int, stop int) int { n := stop - start return rand.Intn(n) + start }(0, len(company_type)-1+1)], "rating": func(start int, stop int) int { n := stop - start return rand.Intn(n) + start }(1, 5+1), "cuisine": company_cuisine[func(start int, stop int) int { n := stop - start return rand.Intn(n) + start }(0, len(company_cuisine)-1+1)]} fmt.Println(business) } }

string_methods

Python

Go

def main(): lower = "hello world" crazy = "HeLLo WoRlD" upper = "HELLO WORLD" lol = "---LOL---" hearts = "🧡💛💚💙💜" arabic_indic_digit = "٠" whitespace = " \v\f\t\r\n" s_hello_s = whitespace + lower + whitespace multiline = lower + "\n" + crazy + "\r\n" + upper + "\n" print(crazy.capitalize()) print(lower.endswith("world")) print(lower.find(" ")) print(lower.find(" ", 2)) print(upper.find(" ", 7, 8)) print(lower.index(" ")) print(lower.index(" ", 2)) print(upper.index(" ", 2, 8)) print(lower.isalnum()) print(hearts.isascii()) print(arabic_indic_digit.isdecimal()) print(arabic_indic_digit.isdigit()) print(lower.islower()) print(arabic_indic_digit.isnumeric()) print(hearts.isprintable()) print(whitespace.isspace()) print(upper.isupper()) print(hearts.join([lower, crazy, upper])) print(crazy.lower()) print(s_hello_s.lstrip() + "|") print(lower.lstrip("h")) print(lower.removeprefix("hello ")) print(lower.removesuffix(" world")) print(lower.replace("world", "gophers")) print(upper.replace("O", "OOOOO", 1)) print(upper.rfind("O")) print(upper.rfind("O", 1)) print(upper.rfind("O", 1, 6)) print(upper.rindex("O")) print(upper.rindex("O", 1)) print(upper.rindex("O", 1, 6)) print(s_hello_s.rstrip() + "|") print(lower.rstrip("d")) print(lower.split()) print(upper.split("L")) print(upper.split("L", 1)) print(multiline.splitlines()) print(upper.startswith("HELLO")) print(s_hello_s.strip() + "|") print(lol.strip("-")) print(crazy.title()) print(crazy.upper()) if __name__ == '__main__': main()

package main import ( "bufio" "errors" "fmt" "strings" "unicode" ) func main() { lower := "hello world" crazy := "HeLLo WoRlD" upper := "HELLO WORLD" lol := "---LOL---" hearts := "🧡💛💚💙💜" arabic_indic_digit := "٠" whitespace := " \u000b\f\t\r\n" s_hello_s := whitespace + lower + whitespace multiline := lower + "\n" + crazy + "\r\n" + upper + "\n" fmt.Println(strings.ToUpper(crazy[0:1]) + strings.ToLower(crazy[1:])) fmt.Println(strings.HasSuffix(lower, "world")) fmt.Println(strings.Index(lower, " ")) fmt.Println(func() int { if r := strings.Index(lower[2:], " "); r != -1 { return r + 2 } return -1 }()) fmt.Println(func() int { if r := strings.Index(upper[7:8], " "); r != -1 { return r + 7 } return -1 }()) fmt.Println(func(X string, sub string) int { if i := strings.Index(X, sub); i != -1 { return i } panic(errors.New("ValueError: substring not found")) }(lower, " ")) fmt.Println(func(X string, sub string, start int) int { if i := func() int { if r := strings.Index(X[start:], sub); r != -1 { return r + start } return -1 }(); i != -1 { return i } panic(errors.New("ValueError: substring not found")) }(lower, " ", 2)) fmt.Println(func(X string, sub string, start int, end int) int { if i := func() int { if r := strings.Index(X[start:end], sub); r != -1 { return r + start } return -1 }(); i != -1 { return i } panic(errors.New("ValueError: substring not found")) }(upper, " ", 2, 8)) fmt.Println(func(X string) bool { for _, r := range X { if !((unicode.IsLetter(r) || unicode.IsDigit(r)) && (unicode.IsDigit(r) || unicode.IsNumber(r))) { return false } } return true }(lower)) fmt.Println(func(X string) bool { for _, r := range X { if r > unicode.MaxASCII { return false } } return true }(hearts)) fmt.Println(func(X string) bool { for _, r := range X { if !unicode.Is(unicode.Nd, r) { return false } } return len(X) != 0 }(arabic_indic_digit)) fmt.Println(func(X string) bool { for _, r := range X { if !unicode.IsDigit(r) { return false } } return len(X) != 0 }(arabic_indic_digit)) fmt.Println(func(X string) bool { lower_found := false for _, r := range X { if !unicode.IsLower(r) { if !unicode.IsSpace(r) { return false } } else { lower_found = true } } return lower_found && len(X) != 0 }(lower)) fmt.Println(func(X string) bool { for _, r := range X { if !(unicode.IsDigit(r) || unicode.IsNumber(r)) { return false } } return len(X) != 0 }(arabic_indic_digit)) fmt.Println(func(X string) bool { for _, r := range X { if !unicode.IsPrint(r) { return false } } return true }(hearts)) fmt.Println(func(X string) bool { for _, r := range X { if !unicode.IsSpace(r) { return false } } return len(X) != 0 }(whitespace)) fmt.Println(func(X string) bool { upper_found := false for _, r := range X { if !unicode.IsUpper(r) { if !unicode.IsSpace(r) { return false } } else { upper_found = true } } return upper_found && len(X) != 0 }(upper)) fmt.Println(strings.Join([]string{lower, crazy, upper}, hearts)) fmt.Println(strings.ToLower(crazy)) fmt.Println(strings.TrimLeftFunc(s_hello_s, unicode.IsSpace) + "|") fmt.Println(strings.TrimLeft(lower, "h")) fmt.Println(strings.TrimPrefix(lower, "hello ")) fmt.Println(strings.TrimSuffix(lower, " world")) fmt.Println(strings.ReplaceAll(lower, "world", "gophers")) fmt.Println(strings.Replace(upper, "O", "OOOOO", 1)) fmt.Println(strings.LastIndex(upper, "O")) fmt.Println(func() int { if r := strings.LastIndex(upper[1:], "O"); r != -1 { return r + 1 } return -1 }()) fmt.Println(func() int { if r := strings.LastIndex(upper[1:6], "O"); r != -1 { return r + 1 } return -1 }()) fmt.Println(func(X string, sub string) int { if i := strings.LastIndex(X, sub); i != -1 { return i } panic(errors.New("ValueError: substring not found")) }(upper, "O")) fmt.Println(func(X string, sub string, start int) int { if i := func() int { if r := strings.LastIndex(X[start:], sub); r != -1 { return r + start } return -1 }(); i != -1 { return i } panic(errors.New("ValueError: substring not found")) }(upper, "O", 1)) fmt.Println(func(X string, sub string, start int, end int) int { if i := func() int { if r := strings.LastIndex(X[start:end], sub); r != -1 { return r + start } return -1 }(); i != -1 { return i } panic(errors.New("ValueError: substring not found")) }(upper, "O", 1, 6)) fmt.Println(strings.TrimRightFunc(s_hello_s, unicode.IsSpace) + "|") fmt.Println(strings.TrimRight(lower, "d")) fmt.Println(strings.Fields(lower)) fmt.Println(strings.Split(upper, "L")) fmt.Println(strings.SplitN(upper, "L", 1)) fmt.Println(func(s string) (lines []string) { sc := bufio.NewScanner(strings.NewReader(s)) for sc.Scan() { lines = append(lines, sc.Text()) } return }(multiline)) fmt.Println(strings.HasPrefix(upper, "HELLO")) fmt.Println(strings.TrimSpace(s_hello_s) + "|") fmt.Println(strings.Trim(lol, "-")) fmt.Println(func(s string) string { ws := true var sb strings.Builder for _, r := range s { if unicode.IsSpace(r) { ws = true sb.WriteRune(r) } else if ws { ws = false sb.WriteRune(unicode.ToUpper(r)) } else { sb.WriteRune(unicode.ToLower(r)) } } return sb.String() }(crazy)) fmt.Println(strings.ToUpper(crazy)) }

list_methods

Python

Go

def main(): l1 = [1] l2 = ["hello", "how", "are", "you?"] l3 = [6.2, 1.6, 1.2, 20.1] l1.append(2) print(l1) l1.extend([4, 5]) print(l1) l1.insert(3, 3) print(l1) print(l1.index(2)) print(l1.count(3)) l1.remove(3) print(l1) while l1: print(l1.pop()) l3.clear() print(l3) l1.sort() print(l1) l2.sort() print(l2) l3.sort() print(l3) l3.sort(reverse=True) print(l3) l2.reverse() print(l2) l4 = l2.copy() l4.pop() print(l4) print(l2) if __name__ == '__main__': main()

package main import ( "errors" "fmt" "reflect" "sort" ) func main() { l1 := []int{1} l2 := []string{"hello", "how", "are", "you?"} l3 := []float64{6.2, 1.6, 1.2, 20.1} l1 = append(l1, 2) fmt.Println(l1) l1 = append(l1, []int{4, 5}...) fmt.Println(l1) l1 = append(l1, 3) copy(l1[3+1:], l1[3:]) l1[3] = 3 fmt.Println(l1) fmt.Println(func() int { for i, val := range l1 { if val == 2 { return i } } panic(errors.New("ValueError: element not found")) }()) fmt.Println(func() int { n := 0 for _, v := range l1 { if v == 3 { n += 1 } } return n }()) func(s *[]int, x int) { for i, val := range *s { if reflect.DeepEqual(val, x) { *s = append((*s)[:i], (*s)[i+1:]...) return } } panic(errors.New("ValueError: element not found")) }(&l1, 3) fmt.Println(l1) for len(l1) != 0 { fmt.Println(func(s *[]int) int { i := len(*s) - 1 popped := (*s)[i] *s = (*s)[:i] return popped }(&l1)) } l3 = nil fmt.Println(l3) sort.Ints(l1) fmt.Println(l1) sort.Strings(l2) fmt.Println(l2) sort.Float64s(l3) fmt.Println(l3) sort.Sort(sort.Reverse(sort.Float64Slice(l3))) fmt.Println(l3) func(arr []string) { for i, j := 0, len(arr)-1; i < j; i, j = i+1, j-1 { arr[i], arr[j] = arr[j], arr[i] } }(l2) fmt.Println(l2) l4 := func(s *[]string) (tmp []string) { tmp = append(tmp, *s...) return }(&l2) func(s *[]string) string { i := len(*s) - 1 popped := (*s)[i] *s = (*s)[:i] return popped }(&l4) fmt.Println(l4) fmt.Println(l2) }

set_methods

Python

Go

def main(): a = {1, 2, 3, 4} b = {4, 5, 6} b.add(7) print(a.union(b)) print(a.intersection(b)) print(a.difference(b)) print(a.symmetric_difference(b)) print(a.issubset(b)) print(a.issuperset(b)) if __name__ == '__main__': main()

package main import "fmt" func main() { a := map[int]struct{}{1: {}, 2: {}, 3: {}, 4: {}} b := map[int]struct{}{4: {}, 5: {}, 6: {}} b[7] = struct{}{} fmt.Println(func(s1 map[int]struct{}, s2 map[int]struct{}) map[interface{}]struct{} { union := map[interface{}]struct{}{} for elt := range s1 { union[elt] = struct{}{} } for elt := range s2 { union[elt] = struct{}{} } return union }(a, b)) fmt.Println(func(s1 map[int]struct{}, s2 map[int]struct{}) map[interface{}]struct{} { intersection := map[interface{}]struct{}{} for elt := range s1 { if func() bool { _, ok := s2[elt] return ok }() { intersection[elt] = struct{}{} } } return intersection }(a, b)) fmt.Println(func(s1 map[int]struct{}, s2 map[int]struct{}) map[interface{}]struct{} { difference := map[interface{}]struct{}{} for elt := range s1 { if !func() bool { _, ok := s2[elt] return ok }() { difference[elt] = struct{}{} } } return difference }(a, b)) fmt.Println(func(s1 map[int]struct{}, s2 map[int]struct{}) map[interface{}]struct{} { symmetric_difference := map[interface{}]struct{}{} for elt := range s1 { if !func() bool { _, ok := s2[elt] return ok }() { symmetric_difference[elt] = struct{}{} } } for elt := range s2 { if !func() bool { _, ok := s1[elt] return ok }() { symmetric_difference[elt] = struct{}{} } } return symmetric_difference }(a, b)) fmt.Println(func(s1 map[int]struct{}, s2 map[int]struct{}) bool { for elt := range s1 { if !func() bool { _, ok := s2[elt] return ok }() { return false } } return true }(a, b)) fmt.Println(func(s1 map[int]struct{}, s2 map[int]struct{}) bool { for elt := range s2 { if !func() bool { _, ok := s1[elt] return ok }() { return false } } return true }(a, b)) }

global_code

Python	Go
A = [1, 2, 3] for i, x in enumerate(A): A[i] += x B = A[0] C = A[0] D: int = 3 while C < A[2]: C += 1 if C == A[2]: print('True') def main(): print("Main started") print(A) print(B) print(C) print(D) if __name__ == '__main__': main()	package main import "fmt" var ( A = []int{1, 2, 3} B int C int D int ) func init() { for i, x := range A { A[i] += x } B = A[0] C = A[0] D = 3 for C < A[2] { C += 1 } if C == A[2] { fmt.Println("True") } } func main() { fmt.Println("Main started") fmt.Println(A) fmt.Println(B) fmt.Println(C) fmt.Println(D) }

boolnumcompare

Python	Go
def main(): print(1 == True) print(1 == False) print(0 == True) print(0 == False) print() print(1. == True) print(1. == False) print(0. == True) print(0. == False) print() print(1+0j == True) print(1+0j == False) print(0+0j == True) print(0+0j == False) print() print(2 == True) if __name__ == '__main__': main()	package main import "fmt" func main() { fmt.Println(1 == 1) fmt.Println(1 == 0) fmt.Println(0 == 1) fmt.Println(0 == 0) fmt.Println() fmt.Println(1.0 == 1) fmt.Println(1.0 == 0) fmt.Println(0.0 == 1) fmt.Println(0.0 == 0) fmt.Println() fmt.Println(1+0.0i == 1) fmt.Println(1+0.0i == 0) fmt.Println(0+0.0i == 1) fmt.Println(0+0.0i == 0) fmt.Println() fmt.Println(2 == 1) }

add

Python	Go
def main(): print(add(2, 2)) def add(a: int, b: int) -> int: return a + b if __name__ == '__main__': main()	package main import "fmt" func main() { fmt.Println(add(2, 2)) } func add(a int, b int) int { return a + b }

exponents

Python	Go
def main(): print(2 ** 8) x = [2, 4] print(x[0] ** x[1]) if __name__ == '__main__': main()	package main import ( "fmt" "math" ) func main() { fmt.Println(math.Pow(2, 8)) x := []int{2, 4} fmt.Println(math.Pow(float64(x[0]), float64(x[1]))) }

variables

Python	Go
def main(): a = 3 b = 7 a = a + b print(a + b) another_scope() def another_scope(): a = 1 b = 12 a = a + b print(a + b) if __name__ == '__main__': main()	package main import "fmt" func main() { a := 3 b := 7 a = a + b fmt.Println(a + b) another_scope() } func another_scope() { a := 1 b := 12 a = a + b fmt.Println(a + b) }

floats

Python	Go
def main(): a = 7 b = 3 c = 4.5 print(a / b) print(a // b) print(a / c) print(a // c) print(a + b) print(a + c) if __name__ == '__main__': main()	package main import ( "fmt" "math" ) func main() { a := 7 b := 3 c := 4.5 fmt.Println(float64(a) / float64(b)) fmt.Println(a / b) fmt.Println(float64(a) / c) fmt.Println(math.Floor(float64(a) / c)) fmt.Println(a + b) fmt.Println(float64(a) + c) }

numlist

Python	Go
def main(): a = [1, 2, 3] print(a[0]) print(a[1]) print(a[2]) a.append(4) print(a[3]) a += [5, 6, 7] a = a + [8, 9, 10] print(a[4]) print(a[-1]) if __name__ == '__main__': main()	package main import "fmt" func main() { a := []int{1, 2, 3} fmt.Println(a[0]) fmt.Println(a[1]) fmt.Println(a[2]) a = append(a, 4) fmt.Println(a[3]) a = append(a, []int{5, 6, 7}...) a = append(a, []int{8, 9, 10}...) fmt.Println(a[4]) fmt.Println(a[len(a)-1]) }

loops

Python	Go
def main(): a = [1, 2, 3] for v in a: print(v) for i, v in enumerate(a): print(i + v) for i in range(5): print(i) for i in range(10, 15): print(i) for i in range(10, 15, 2): print(i) for j in range(15, 10, -1): print(j) for j in range(15, 10, -2): print(j) if __name__ == '__main__': main()	package main import "fmt" func main() { a := []int{1, 2, 3} for _, v := range a { fmt.Println(v) } for i, v := range a { fmt.Println(i + v) } for i := 0; i < 5; i++ { fmt.Println(i) } for i := 10; i < 15; i++ { fmt.Println(i) } for i := 10; i < 15; i += 2 { fmt.Println(i) } for j := 15; j > 10; j-- { fmt.Println(j) } for j := 15; j > 10; j -= 2 { fmt.Println(j) } }

strings

Python	Go
def main(): a = "hello" b = "world" c = a + " " + b print(c) print(double_it(c)) print(c[1]) print(c[1:6]) def double_it(c: str) -> str: return c + c if __name__ == '__main__': main()	package main import "fmt" func main() { a := "hello" b := "world" c := a + " " + b fmt.Println(c) fmt.Println(double_it(c)) fmt.Println(string(c[1])) fmt.Println(c[1:6]) } func double_it(c string) string { return c + c }

logical

Python	Go
def main(): a = True b = False print(a) print(b) print(a and b) print(a or b) print(not a) print(not b) print(a and not b) print(a or not b) if __name__ == '__main__': main()	package main import "fmt" func main() { a := true b := false fmt.Println(a) fmt.Println(b) fmt.Println(a && b) fmt.Println(a || b) fmt.Println(!a) fmt.Println(!b) fmt.Println(a && !b) fmt.Println(a || !b) }

maths

Python	Go
import math def main(): print(math.sin(3)) print(math.cosh(3)) print(math.pi) print(math.acosh(6)) print(math.atan2(4, 7)) if __name__ == '__main__': main()	package main import ( "fmt" "math" ) func main() { fmt.Println(math.Sin(3)) fmt.Println(math.Cosh(3)) fmt.Println(math.Pi) fmt.Println(math.Acosh(6)) fmt.Println(math.Atan2(4, 7)) }

requestslib

Python	Go
import requests def main(): resp = requests.get("http://tour.golang.org/welcome/1") print(resp.text) if __name__ == '__main__': main()	package main import ( "fmt" "io/ioutil" "net/http" ) func main() { resp, err := http.Get("http://tour.golang.org/welcome/1") if err != nil { panic(err) } defer resp.Body.Close() fmt.Println(func() string { body, err := ioutil.ReadAll(resp.Body) if err != nil { panic(err) } return string(body) }()) }

conditionals

Python	Go
def main(): a = 7 b = add(a, -2) if a > b: print("It's bigger") elif a == b: print("They're equal") else: print("It's smaller") def add(a: int, b: int) -> int: return a + b if __name__ == '__main__': main()	package main import "fmt" func main() { a := 7 b := add(a, -2) if a > b { fmt.Println("It's bigger") } else if a == b { fmt.Println("They're equal") } else { fmt.Println("It's smaller") } } func add(a int, b int) int { return a + b }

fstrings

Python

Go

def main(): name = "Michael" age = 24 print(f"My name is {name} and I am {age} years old. Later this year I'll be {age + 1}!") if __name__ == '__main__': main()

package main import ( "bytes" "fmt" "text/template" ) func main() { name := "Michael" age := 24 fmt.Println(func() string { var buf bytes.Buffer err := template.Must(template.New("f").Parse("My name is {{.name}} and I am {{.age}} years old. Later this year I'll be {{.expr1}}!")). Execute(&buf, map[string]interface{}{"name": name, "age": age, "expr1": age + 1}) if err != nil { panic(err) } return buf.String() }()) }

nestedfstrings

Python

Go

def main(): name = "Michael" age = 24 print(f"My name is {name} and I am {age} years old. Later this year I'll be {f'{age + 1}'}!") if __name__ == '__main__': main()

package main import ( "bytes" "fmt" "text/template" ) func main() { name := "Michael" age := 24 fmt.Println(func() string { var buf bytes.Buffer err := template.Must(template.New("f").Parse("My name is {{.name}} and I am {{.age}} years old. Later this year I'll be {{.expr1}}!")). Execute(&buf, map[string]interface{}{"name": name, "age": age, "expr1": func() string { var buf bytes.Buffer err := template.Must(template.New("f").Parse("{{.expr1}}")). Execute(&buf, map[string]interface{}{"expr1": age + 1}) if err != nil { panic(err) } return buf.String() }()}) if err != nil { panic(err) } return buf.String() }()) }

dictionary

Python	Go
def main(): a = {"name": "Michael", "age": 24, 1337: True} print(a) a["sleepiness"] = 1.0 del a[1337] for k, v in a.items(): print(k) print(v)	package main import "fmt" func main() { a := map[interface{}]interface{}{"name": "Michael", "age": 24, 1337: true} fmt.Println(a) a["sleepiness"] = 1.0 delete(a, 1337) for k, v := range a { fmt.Println(k) fmt.Println(v) } }

writefile

Python

Go

def main(): with open("file_1.tmp", "w+") as f: f.write("This file was created in w+ mode\n") with open("file_2.tmp", "x") as f: f.write("This file was created by x mode\n") with open("file_2.tmp", "w") as f: f.write("This file was created by x mode and then overwritten in w mode\n") with open("file_2.tmp", "a") as f: f.write("... And then appended to in a mode\n") with open("file_2.tmp", "r") as f: print(f.read()) with open("file_3.tmp", "a+") as f: f.write("This file was created in a+ mode\n") with open("file_4.tmp", "x+") as f: f.write("This file was created by x+ mode\n") with open("file_5.tmp", "wb+") as f: f.write(b"This file was created in wb+ mode\n") with open("file_6.tmp", "xb") as f: f.write(b"This file was created by xb mode\n") with open("file_6.tmp", "wb") as f: f.write(b"This file was created by xb mode and then overwritten in wb mode\n") with open("file_6.tmp", "ab") as f: f.write(b"... And then appended to in ab mode\n") with open("file_6.tmp", "rb") as f: print(f.read().decode()) with open("file_7.tmp", "ab+") as f: f.write(b"This file was created in ab+ mode\n") with open("file_8.tmp", "xb+") as f: f.write(b"This file was created by xb+ mode\n") if __name__ == '__main__': main()

package main import ( "fmt" "io/ioutil" "os" ) func main() { func() { f := func() *os.File { f, err := os.OpenFile("file_1.tmp", os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.WriteString("This file was created in w+ mode\n") if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_2.tmp", os.O_WRONLY|os.O_EXCL|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.WriteString("This file was created by x mode\n") if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_2.tmp", os.O_WRONLY|os.O_TRUNC, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.WriteString( "This file was created by x mode and then overwritten in w mode\n", ) if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_2.tmp", os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.WriteString("... And then appended to in a mode\n") if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_2.tmp", os.O_RDONLY, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() fmt.Println(func() string { content, err := ioutil.ReadAll(f) if err != nil { panic(err) } return string(content) }()) }() func() { f := func() *os.File { f, err := os.OpenFile("file_3.tmp", os.O_RDWR|os.O_APPEND|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.WriteString("This file was created in a+ mode\n") if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_4.tmp", os.O_RDWR|os.O_EXCL|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.WriteString("This file was created by x+ mode\n") if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_5.tmp", os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.Write([]byte("This file was created in wb+ mode\n")) if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_6.tmp", os.O_WRONLY|os.O_EXCL|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.Write([]byte("This file was created by xb mode\n")) if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_6.tmp", os.O_WRONLY|os.O_TRUNC, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.Write( []byte("This file was created by xb mode and then overwritten in wb mode\n"), ) if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_6.tmp", os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.Write([]byte("... And then appended to in ab mode\n")) if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_6.tmp", os.O_RDONLY, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() fmt.Println(string(func() []byte { content, err := ioutil.ReadAll(f) if err != nil { panic(err) } return content }())) }() func() { f := func() *os.File { f, err := os.OpenFile("file_7.tmp", os.O_RDWR|os.O_APPEND|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.Write([]byte("This file was created in ab+ mode\n")) if err != nil { panic(err) } return n }() }() func() { f := func() *os.File { f, err := os.OpenFile("file_8.tmp", os.O_RDWR|os.O_EXCL|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() func() int { n, err := f.Write([]byte("This file was created by xb+ mode\n")) if err != nil { panic(err) } return n }() }() }

pass

Python	Go
def main(): pass if __name__ == '__main__': main()	package main func main() { }

ellipsis

Python	Go
def main(): ... if __name__ == '__main__': main()	package main func main() { }

missingreturntype

Python	Go
def main(): print(add(1, 3)) def add(a: int, b: int): return a + b	package main import "fmt" func main() { fmt.Println(add(1, 3)) } func add(a int, b int) int { return a + b }

continuestmt

Python	Go
def main(): for i in range(10): if i < 3 or i > 7: continue print(i) if __name__ == '__main__': main()	package main import "fmt" func main() { for i := 0; i < 10; i++ { if i < 3 || i > 7 { continue } fmt.Println(i) } }

breakstmt

Python	Go
def main(): for i in range(10): if i > 7: break print(i) if __name__ == '__main__': main()	package main import "fmt" func main() { for i := 0; i < 10; i++ { if i > 7 { break } fmt.Println(i) } }

whileloop

Python

Go

def main(): i = 0 while True: print(i) i += 1 if i > 5: break j = 10 while j < 100: print(j) j += 10 while 1: print(j + i) break while 0.1: print(j + i) break while 0: print("This never executes") while 0.0: print("This never executes") while None: print("This never executes") while False: print("This never executes") while "": print("This never executes") while "hi": print("This executes") break if __name__ == '__main__': main()

package main import "fmt" func main() { i := 0 for { fmt.Println(i) i += 1 if i > 5 { break } } j := 10 for j < 100 { fmt.Println(j) j += 10 } for { fmt.Println(j + i) break } for { fmt.Println(j + i) break } for false { fmt.Println("This never executes") } for false { fmt.Println("This never executes") } for false { fmt.Println("This never executes") } for false { fmt.Println("This never executes") } for false { fmt.Println("This never executes") } for { fmt.Println("This executes") break } }

sets

Python	Go
def main(): s = {1, 2, 3} x = 1 print(len(s)) print(x in s) print(x not in s) if __name__ == '__main__': main()	package main import "fmt" func main() { s := map[int]struct{}{1: {}, 2: {}, 3: {}} x := 1 fmt.Println(len(s)) fmt.Println(func() bool { _, ok := s[x] return ok }()) fmt.Println(!func() bool { _, ok := s[x] return ok }()) }

contains

Python

Go

def main(): a = [1, 2, 3] print(1 in a) print(4 in a) print(5 not in a) b = "hello world" print("hello" in b) print("Hello" not in b) c = {"hello": 1, "world": 2} print("hello" in c) print("Hello" not in c) d = b'hello world' print(b'hello' in d) print(b'Hello' not in d) e = {1, 2, 3, "hello"} print("hello" in e) print(4 not in e) if __name__ == '__main__': main()

package main import ( "bytes" "fmt" "strings" ) func main() { a := []int{1, 2, 3} fmt.Println(func() int { for i, v := range a { if v == 1 { return i } } return -1 }() != -1) fmt.Println(func() int { for i, v := range a { if v == 4 { return i } } return -1 }() != -1) fmt.Println(func() int { for i, v := range a { if v == 5 { return i } } return -1 }() == -1) b := "hello world" fmt.Println(strings.Contains(b, "hello")) fmt.Println(!strings.Contains(b, "Hello")) c := map[string]int{"hello": 1, "world": 2} fmt.Println(func() bool { _, ok := c["hello"] return ok }()) fmt.Println(!func() bool { _, ok := c["Hello"] return ok }()) d := []byte("hello world") fmt.Println(bytes.Contains(d, []byte("hello"))) fmt.Println(!bytes.Contains(d, []byte("Hello"))) e := map[interface{}]struct{}{1: {}, 2: {}, 3: {}, "hello": {}} fmt.Println(func() bool { _, ok := e["hello"] return ok }()) fmt.Println(!func() bool { _, ok := e[4] return ok }()) }

tryexcept

Python

Go

def main(): a = [1, 2, 3] for index in range(4): try: print(a[index]) if index == 1: raise ValueError(index) except IndexError: print("That index was out of bounds") except (NotImplementedError, RuntimeError): print("This won't actually happen...") except Exception as e: print("Some other exception occurred") print(e) if __name__ == '__main__': main()

package main import ( "fmt" "strings" ) func main() { a := []int{1, 2, 3} for index := 0; index < 4; index++ { func() { defer func() { if r := recover(); r != nil { if err, ok := r.(error); ok { if strings.HasPrefix(err.Error(), "IndexError") || strings.HasPrefix(err.Error(), "runtime error: index out of range") { fmt.Println("That index was out of bounds") return } else if strings.HasPrefix(err.Error(), "NotImplementedError") || (strings.HasPrefix(err.Error(), "RuntimeError") || strings.HasPrefix(err.Error(), "runtime error")) { fmt.Println("This won't actually happen...") return } else { e := err fmt.Println("Some other exception occurred") fmt.Println(e) return } } panic(r) } }() fmt.Println(a[index]) if index == 1 { panic(fmt.Errorf("ValueError: %v", index)) } }() } }

tryfinally

Python

Go

def main(): a = [1, 2, 3] for index in range(4): try: print(a[index]) except Exception: pass finally: print("Finished an iteration") for index in range(4): try: print(a[index]) finally: print("Finished an iteration") if __name__ == '__main__': main()

package main import "fmt" func main() { a := []int{1, 2, 3} for index := 0; index < 4; index++ { func() { defer func() { fmt.Println("Finished an iteration") }() defer func() { if r := recover(); r != nil { if _, ok := r.(error); ok { return } panic(r) } }() fmt.Println(a[index]) }() } for index := 0; index < 4; index++ { func() { defer func() { fmt.Println("Finished an iteration") }() fmt.Println(a[index]) }() } }

asserts

Python	Go
def main(): assert 1 + 1 == 2 assert True assert 1 + 3 == 5, "Math must be broken" if __name__ == '__main__': main()	package main import ( "errors" "fmt" ) func main() { if !(1+1 == 2) { panic(errors.New("AssertionError")) } if !true { panic(errors.New("AssertionError")) } if !(1+3 == 5) { panic(fmt.Errorf("AssertionError: %v", "Math must be broken")) } }

classes

Python

Go

class Welcome: greeting: str instructions: list[str] def __init__(self, greeting: str, instructions: list[str]) -> None: self.greeting = greeting self.instructions = instructions def greet(self): print(self.greeting) for instruction in self.instructions: print(instruction) def main(): welcome = Welcome("Hello World", [ "This is a class!", "Support will be limited at first.", "Still, I hope you'll find them useful." ]) welcome.greet() if __name__ == '__main__': main()

package main import "fmt" type Welcome struct { greeting string instructions []string } func NewWelcome(greeting string, instructions []string) (self *Welcome) { self = new(Welcome) self.greeting = greeting self.instructions = instructions return } func (self *Welcome) greet() { fmt.Println(self.greeting) for _, instruction := range self.instructions { fmt.Println(instruction) } } func main() { welcome := NewWelcome( "Hello World", []string{ "This is a class!", "Support will be limited at first.", "Still, I hope you'll find them useful.", }, ) welcome.greet() }

globals

Python

Go

SITE = "https://www.google.com/" NAME = ["Michael", "Wayne", "Phelps"] KEYS = {1: 2, 3: 4} AGE = 1000 BIRTH_YEAR = 2050 def main(): global AGE print(SITE) print(NAME) print(BIRTH_YEAR) print(KEYS) print(AGE) AGE = 20 # This should use the variable from the global scope other_1() print(AGE) other_2() def other_1(): AGE = 200 # This should declare a new variable age print(AGE) def other_2(): print(AGE) # This should still be able to access the global if __name__ == '__main__': main()

package main import "fmt" var ( SITE = "https://www.google.com/" NAME = []string{"Michael", "Wayne", "Phelps"} KEYS = map[int]int{1: 2, 3: 4} AGE = 1000 BIRTH_YEAR = 2050 ) func main() { fmt.Println(SITE) fmt.Println(NAME) fmt.Println(BIRTH_YEAR) fmt.Println(KEYS) fmt.Println(AGE) AGE = 20 other_1() fmt.Println(AGE) other_2() } func other_1() { AGE := 200 fmt.Println(AGE) } func other_2() { fmt.Println(AGE) }

asyncawait

Python	Go
import asyncio async def myAsyncFunction() -> int: await asyncio.sleep(2) return 2 async def main(): r = await myAsyncFunction() print(r) if __name__ == '__main__': asyncio.run(main())	package main import ( "fmt" "time" ) func myAsyncFunction() <-chan int { r := make(chan int) go func() { defer close(r) time.Sleep(time.Second * 2) r <- 2 }() return r } func main() { r := <-myAsyncFunction() fmt.Println(r) }

yields

Python

Go

def main(): my_gen = gen() for x in my_gen: print("Received next number!") print(x) def gen(): print("Yielding next number...") yield 1 print("Yielding next number...") yield 2 print("Yielding next number...") yield 3 if __name__ == '__main__': main()

package main import "fmt" func main() { my_gen := gen() for x, ok := <-my_gen(); ok; x, ok = <-my_gen() { fmt.Println("Received next number!") fmt.Println(x) } } func gen() func() <-chan int { wait := make(chan struct{}) yield := make(chan int) go func() { defer close(yield) <-wait fmt.Println("Yielding next number...") yield <- 1 <-wait fmt.Println("Yielding next number...") yield <- 2 <-wait fmt.Println("Yielding next number...") yield <- 3 <-wait }() return func() <-chan int { wait <- struct{}{} return yield } }

isvseql

Python	Go
def main(): a = [1, 2, 3] b = [1, 2, 3] print(a == b) # True print(a != b) # False print(a is a) # True print(a is b) # False print(a is not a) # False print(a is not b) # True if __name__ == '__main__': main()	package main import ( "fmt" "reflect" ) func main() { a := []int{1, 2, 3} b := []int{1, 2, 3} fmt.Println(reflect.DeepEqual(a, b)) fmt.Println(!reflect.DeepEqual(a, b)) fmt.Println(&a == &a) fmt.Println(&a == &b) fmt.Println(&a != &a) fmt.Println(&a != &b) }

matchcase

Python	Go
def main(): a = 1 match a: case 1: print(1) case 2: print(2) case 3: print(3) match a: case 4: print("Never gonna happen") case _: print("Nice, defaults!") if __name__ == '__main__': main()	package main import "fmt" func main() { a := 1 switch a { case 1: fmt.Println(1) case 2: fmt.Println(2) case 3: fmt.Println(3) } switch a { case 4: fmt.Println("Never gonna happen") default: fmt.Println("Nice, defaults!") } }

defaultargs

Python	Go
def main(): a = increment(1) print(a) b = increment(a, 2) print(b) c = increment(a, decrement=True, amount=3) print(c) def increment(n: int, amount: int = 1, decrement: bool = False) -> int: if decrement: return n - amount return n + amount if __name__ == '__main__': main()	package main import "fmt" func main() { a := increment(1, 1, false) fmt.Println(a) b := increment(a, 2, false) fmt.Println(b) c := increment(a, 3, true) fmt.Println(c) } func increment(n int, amount int, decrement bool) int { if decrement { return n - amount } return n + amount }

walrus

Python

Go

def main(): if (a := some_func()) == 7: print(a) for x in (y := [1, 2, 3]): print(y) print(x) match j := 5: case 5: print(j) while (t1 := thing_1()) < 5 and (t2 := thing_2()) == 3: print(t1) print(t2) def some_func(): return 7 call_count = 0 def thing_1(): global call_count call_count += 1 return call_count def thing_2(): return 3 if __name__ == '__main__': main()

package main import "fmt" func main() { if a := some_func(); a == 7 { fmt.Println(a) } y := []int{1, 2, 3} for _, x := range y { fmt.Println(y) fmt.Println(x) } switch j := 5; j { case 5: fmt.Println(j) } for t1, t2 := thing_1(), thing_2(); t1 < 5 && t2 == 3; t1, t2 = thing_1(), thing_2() { fmt.Println(t1) fmt.Println(t2) } } func some_func() int { return 7 } var call_count = 0 func thing_1() int { call_count += 1 return call_count } func thing_2() int { return 3 }

truthiness

Python

Go

def main(): if a := 1: print(a) if c := "": print(c) if d := b"": print(d) if e := "Hello": print(e) if f := b"Goodbye": print(f) if g := 1.0: print(g) if h := 1j: print(h) if i := 0.0: print(i) if j := 0j: print(j) if k := []: print(k) if l := [1, 2, 3]: print(l) if m := True: print(m) if n := False: print(n) if o := (): print(o) if p := (1, 2, 3): print(p) if q := set(): print(q) if r := {1, 2, 3}: print(r) if s := {}: print(s) if t := {1: 2}: print(t) if __name__ == '__main__': main()

package main import "fmt" func main() { if a := 1; a != 0 { fmt.Println(a) } if c := ""; len(c) != 0 { fmt.Println(c) } if d := []byte(""); len(d) != 0 { fmt.Println(d) } if e := "Hello"; len(e) != 0 { fmt.Println(e) } if f := []byte("Goodbye"); len(f) != 0 { fmt.Println(f) } if g := 1.0; g != 0 { fmt.Println(g) } if h := 1.0i; h != 0 { fmt.Println(h) } if i := 0.0; i != 0 { fmt.Println(i) } if j := 0.0i; j != 0 { fmt.Println(j) } if k := []interface{}{}; len(k) != 0 { fmt.Println(k) } if l := []int{1, 2, 3}; len(l) != 0 { fmt.Println(l) } if m := true; m { fmt.Println(m) } if n := false; n { fmt.Println(n) } if o := [0]interface{}{}; len(o) != 0 { fmt.Println(o) } if p := [3]int{1, 2, 3}; len(p) != 0 { fmt.Println(p) } if q := map[interface{}]struct{}{}; len(q) != 0 { fmt.Println(q) } if r := map[int]struct{}{1: {}, 2: {}, 3: {}}; len(r) != 0 { fmt.Println(r) } if s := map[interface{}]interface{}{}; len(s) != 0 { fmt.Println(s) } if t := map[int]int{1: 2}; len(t) != 0 { fmt.Println(t) } }

minmax

Python

Go

def main(): print(max([1, 2, 3])) print(min([1, 2, 3])) print(max("a", "b", "c")) print(min("a", "b", "c")) if __name__ == '__main__': main()

package main import "fmt" func main() { fmt.Println(func() (m int) { for i, e := range []int{1, 2, 3} { if i == 0 || e > m { m = e } } return }()) fmt.Println(func() (m int) { for i, e := range []int{1, 2, 3} { if i == 0 || e < m { m = e } } return }()) fmt.Println(func() (m string) { for i, e := range []string{"a", "b", "c"} { if i == 0 || e > m { m = e } } return }()) fmt.Println(func() (m string) { for i, e := range []string{"a", "b", "c"} { if i == 0 || e < m { m = e } } return }()) }

sum

Python	Go
def main(): print(sum([1, 2, 3])) print(sum([1.5, 2.6, 3.7])) print(sum([1j, 2j, 3j])) if __name__ == '__main__': main()	package main import "fmt" func main() { fmt.Println(func() (s int) { for _, e := range []int{1, 2, 3} { s += e } return }()) fmt.Println(func() (s float64) { for _, e := range []float64{1.5, 2.6, 3.7} { s += e } return }()) fmt.Println(func() (s complex128) { for _, e := range []complex128{1.0i, 2.0i, 3.0i} { s += e } return }()) }

reverse

Python

Go

def main(): a = [1, 2, 3, 4, 5] for x in reversed(a): print(x) for x in a: print(x) a.reverse() for x in a: print(x) if __name__ == '__main__': main()

package main import "fmt" func main() { a := []int{1, 2, 3, 4, 5} for _, x := range func(arr []int) []int { arr2 := make([]int, len(arr)) for i, e := range arr { arr2[len(arr)-i-1] = e } return arr2 }(a) { fmt.Println(x) } for _, x := range a { fmt.Println(x) } func(arr []int) { for i, j := 0, len(arr)-1; i < j; i, j = i+1, j-1 { arr[i], arr[j] = arr[j], arr[i] } }(a) for _, x := range a { fmt.Println(x) } }

listcomp

Python

Go

def main(): a = [x for x in range(10)] b = [x for x in range(10) if x % 2 == 0] c = [x if x % 2 == 0 else 777 for x in range(10)] d = [x for i, x in enumerate(c) if i % 2 == 0 if i % 3 == 1] e = [(x, y) for x in c for y in d] f = [(x, y) for x in c for y in next_five_numbers_times_two(x)] g = [(i, j) for i in range(10) for j in range(i)] print(a) print(b) print(c) print(d) print(e) print(f) print(g) def next_five_numbers_times_two(a: int) -> list[int]: return [(a + i) * 2 for i in range(1, 6)] if __name__ == '__main__': main()

package main import "fmt" func main() { a := func() (elts []int) { for x := 0; x < 10; x++ { elts = append(elts, x) } return }() b := func() (elts []int) { for x := 0; x < 10; x++ { if x%2 == 0 { elts = append(elts, x) } } return }() c := func() (elts []int) { for x := 0; x < 10; x++ { elts = append(elts, func() int { if x%2 == 0 { return x } return 777 }()) } return }() d := func() (elts []int) { for i, x := range c { if i%2 == 0 { if i%3 == 1 { elts = append(elts, x) } } } return }() e := func() (elts [][2]int) { for _, x := range c { for _, y := range d { elts = append(elts, [2]int{x, y}) } } return }() f := func() (elts [][2]int) { for _, x := range c { for _, y := range next_five_numbers_times_two(x) { elts = append(elts, [2]int{x, y}) } } return }() g := func() (elts [][2]int) { for i := 0; i < 10; i++ { for j := 0; j < i; j++ { elts = append(elts, [2]int{i, j}) } } return }() fmt.Println(a) fmt.Println(b) fmt.Println(c) fmt.Println(d) fmt.Println(e) fmt.Println(f) fmt.Println(g) } func next_five_numbers_times_two(a int) []int { return func() (elts []int) { for i := 1; i < 6; i++ { elts = append(elts, (a+i)*2) } return }() }

dictcomp

Python	Go
def main(): a = {(x, y): x*y for x in range(20) for y in range(5) if x*y != 0} for k, v in a.items(): print(k, v) if __name__ == '__main__': main()	package main import "fmt" func main() { a := func() (d map[[2]int]int) { d = make(map[[2]int]int) for x := 0; x < 20; x++ { for y := 0; y < 5; y++ { if x*y != 0 { d[[2]int{x, y}] = x * y } } } return }() for k, v := range a { fmt.Println(k, v) } }

setcomp

Python

Go

def main(): a = {x for x in range(20, 39)} b = {(x, y) for x in range(100) for y in range(x, x + 5) if x % 39 in a} print(a) print(b) if __name__ == '__main__': main()

package main import "fmt" func main() { a := func() (s map[int]struct{}) { s = make(map[int]struct{}) for x := 20; x < 39; x++ { s[x] = struct{}{} } return }() b := func() (s map[[2]int]struct{}) { s = make(map[[2]int]struct{}) for x := 0; x < 100; x++ { for y := x; y < x+5; y++ { if func() bool { _, ok := a[x%39] return ok }() { s[[2]int{x, y}] = struct{}{} } } } return }() fmt.Println(a) fmt.Println(b) }

generatorexp

Python

Go

def main(): a = ((x, y) for x in range(5) for y in range(x)) b = (w for w in ("Where", "Are", "You?", "And", "I'm", "So", "Sorry")) for l in b: print(l, next(a)) for rest in a: print(rest) if __name__ == '__main__': main()

package main import "fmt" func main() { a := func() func() <-chan [2]int { wait := make(chan struct{}) yield := make(chan [2]int) go func() { defer close(yield) <-wait for x := 0; x < 5; x++ { for y := 0; y < x; y++ { yield <- [2]int{x, y} <-wait } } }() return func() <-chan [2]int { wait <- struct{}{} return yield } }() b := func() func() <-chan string { wait := make(chan struct{}) yield := make(chan string) go func() { defer close(yield) <-wait for _, w := range [7]string{"Where", "Are", "You?", "And", "I'm", "So", "Sorry"} { yield <- w <-wait } }() return func() <-chan string { wait <- struct{}{} return yield } }() for l, ok := <-b(); ok; l, ok = <-b() { fmt.Println(l, <-a()) } for rest, ok := <-a(); ok; rest, ok = <-a() { fmt.Println(rest) } }

ternary

Python	Go
def main(): a = 1 if True else 2 print(a) if __name__ == '__main__': main()	package main import "fmt" func main() { a := func() int { if true { return 1 } return 2 }() fmt.Println(a) }

isinstance

Python

Go

def main(): a = ["a", 1, "5", 2.3, 1.2j] some_condition = True for x in a: if isinstance(x, (str, float)): print("String or float!") elif isinstance(x, int): print("Integer!") else: print("Dunno!") print(":)") if isinstance(x, str) and some_condition: print("String") elif isinstance(x, int): print("Integer!") else: print("Dunno!!") print(":O") if __name__ == '__main__': main()

package main import "fmt" func main() { a := []interface{}{"a", 1, "5", 2.3, 1.2i} some_condition := true for _, x := range a { switch x.(type) { case string, float64: fmt.Println("String or float!") case int: fmt.Println("Integer!") default: fmt.Println("Dunno!") fmt.Println(":)") } if func() bool { switch x.(type) { case string: return true } return false }() && some_condition { fmt.Println("String") } else { switch x.(type) { case int: fmt.Println("Integer!") default: fmt.Println("Dunno!!") fmt.Println(":O") } } } }

zip

Python

Go

def main(): x = [1, 2, 3] y = [4, 5, 6] zipped = zip(x, y) for pair in zipped: print(pair) if __name__ == '__main__': main()

package main import "fmt" func main() { x := []int{1, 2, 3} y := []int{4, 5, 6} zipped := func() func() <-chan [2]int { wait := make(chan struct{}) yield := make(chan [2]int) go func() { defer close(yield) <-wait for i, e := range x { if i >= len(y) { break } yield <- [2]int{e, y[i]} <-wait } }() return func() <-chan [2]int { wait <- struct{}{} return yield } }() for pair, ok := <-zipped(); ok; pair, ok = <-zipped() { fmt.Println(pair) } }

map

Python

Go

def main(): a = [1, 2, 3] b = map(increment, a) for value in b: print(value) def increment(n: int) -> int: return n + 1 if __name__ == '__main__': main()

package main import "fmt" func main() { a := []int{1, 2, 3} b := func() func() <-chan int { wait := make(chan struct{}) yield := make(chan int) go func() { defer close(yield) <-wait for _, x := range a { yield <- increment(x) <-wait } }() return func() <-chan int { wait <- struct{}{} return yield } }() for value, ok := <-b(); ok; value, ok = <-b() { fmt.Println(value) } } func increment(n int) int { return n + 1 }

repr

Python	Go
def main(): nums = [1, 2, 3, 4, 5, 6, 7, 8, 9] s = repr(nums) print(s + s) if __name__ == '__main__': main()	package main import "fmt" func main() { nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9} s := fmt.Sprintf("%#v", nums) fmt.Println(s + s) }

lambdafunc

Python	Go
def main(): f = lambda x: x * 2 for a in range(10): print((lambda x: x + 1)(a) + f(a)) if __name__ == '__main__': main()	package main import "fmt" func main() { f := func(x int) int { return int(x) * 2 } for a := 0; a < 10; a++ { fmt.Println(func(x int) int { return int(x) + 1 }(a) + f(a)) } }

timemodule

Python	Go
import time def main(): print("Hello") time.sleep(3) print("... time!") if __name__ == '__main__': main()	package main import ( "fmt" "time" ) func main() { fmt.Println("Hello") time.Sleep(3 * time.Second) fmt.Println("... time!") }

exit

Python	Go
import sys def main(): quit() quit(1) exit() exit(1) sys.exit() sys.exit(1) if __name__ == '__main__': main()	package main import "os" func main() { os.Exit(0) os.Exit(1) os.Exit(0) os.Exit(1) os.Exit(0) os.Exit(1) }

retroactive_composite_types

Python

Go

def main(): a = [] a.append(3) b = [] b += a c = {} c["hello"] = 1 d = {} d[1] = 2 d["gonna_be_an_interface"] = "yup" e = set() e.add(1) f = [[]] f[0].append(1) g = {} g[(1, 2)] = 3 h = [] h.append(1) h.append("hi") i = {} i[1] = "lol" i["2"] = "lmao" print(a, b, c, d, e, f, g, h) if __name__ == '__main__': main()

package main import "fmt" func main() { a := []int{} a = append(a, 3) b := []int{} b = append(b, a...) c := map[string]int{} c["hello"] = 1 d := map[interface{}]interface{}{} d[1] = 2 d["gonna_be_an_interface"] = "yup" e := map[int]struct{}{} e[1] = struct{}{} f := [][]int{{}} f[0] = append(f[0], 1) g := map[[2]int]int{} g[[2]int{1, 2}] = 3 h := []interface{}{} h = append(h, 1) h = append(h, "hi") i := map[interface{}]string{} i[1] = "lol" i["2"] = "lmao" fmt.Println(a, b, c, d, e, f, g, h) }

isinstance_gives_type_assertion

Python

Go

def main(): stuff = [1, 5, "hello", 5, 12, 19, 12.5, [1, 2, 3]] write_contents(stuff) items = ["", 0, 1.1] for x in items: if isinstance(x, str): print("See? It's not used here so we don't have a type assertion") elif isinstance(x, int): print("This is very important because go's compiler will complain") else: print("You know, I wouldn't have to worry about this if we had something to remove unused initializations") def write_contents(contents): with open("contents.txt", "w+") as f: for item in contents: if isinstance(item, str): f.write("str: " + item + "\n") elif isinstance(item, int): f.write("int: " + str(item) + "\n") else: f.write("unknown: " + repr(item) + "\n") if __name__ == '__main__': main()

package main import ( "fmt" "os" ) func main() { stuff := []interface{}{1, 5, "hello", 5, 12, 19, 12.5, []int{1, 2, 3}} write_contents(stuff) items := []interface{}{"", 0, 1.1} for _, x := range items { switch x.(type) { case string: fmt.Println("See? It's not used here so we don't have a type assertion") case int: fmt.Println("This is very important because go's compiler will complain") default: fmt.Println("You know, I wouldn't have to worry about this if we had something to remove unused initializations") } } } func write_contents(contents []interface{}) { f := func() *os.File { f, err := os.OpenFile("contents.txt", os.O_RDWR|os.O_TRUNC|os.O_CREATE, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := f.Close(); err != nil { panic(err) } }() for _, item := range contents { switch item := item.(type) { case string: func() int { n, err := f.WriteString("str: " + item + "\n") if err != nil { panic(err) } return n }() case int: func() int { n, err := f.WriteString("int: " + fmt.Sprintf("%v", item) + "\n") if err != nil { panic(err) } return n }() default: func() int { n, err := f.WriteString("unknown: " + fmt.Sprintf("%#v", item) + "\n") if err != nil { panic(err) } return n }() } } }

fileloop

Python

Go

def main(): fh = open("file.txt") for line in fh: print(line) fh.close() with open("file2.txt") as fh2: for line in fh2: print(line) with open("file3.txt", "rb") as fh3: for l in fh3: print(l) if __name__ == '__main__': main()

package main import ( "bufio" "fmt" "io" "os" ) func main() { fh := func() *os.File { f, err := os.OpenFile("file.txt", os.O_RDONLY, 0o777) if err != nil { panic(err) } return f }() if sc, line, err := bufio.NewReader(fh), "", *new(error); true { for { line, err = sc.ReadString('\n') if err != nil && (err == io.EOF && len(line) == 0 || err != io.EOF) { break } fmt.Println(line) } if err != io.EOF { panic(err) } } if err := fh.Close(); err != nil { panic(err) } func() { fh2 := func() *os.File { f, err := os.OpenFile("file2.txt", os.O_RDONLY, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := fh2.Close(); err != nil { panic(err) } }() if sc, line, err := bufio.NewReader(fh2), "", *new(error); true { for { line, err = sc.ReadString('\n') if err != nil && (err == io.EOF && len(line) == 0 || err != io.EOF) { break } fmt.Println(line) } if err != io.EOF { panic(err) } } }() func() { fh3 := func() *os.File { f, err := os.OpenFile("file3.txt", os.O_RDONLY, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := fh3.Close(); err != nil { panic(err) } }() if sc, l, err := bufio.NewReader(fh3), []byte{}, *new(error); true { for { l, err = sc.ReadBytes('\n') if err != nil && (err == io.EOF && len(l) == 0 || err != io.EOF) { break } fmt.Println(l) } if err != io.EOF { panic(err) } } }() }

unpacking

Python	Go
def main(): name = "Michael Wayne Phelps" first, middle, last = name.split() x = [1, 2, 3] a, b, c = x d, e, f = 4, 5, 6 g, h, i = [7, 8, 9] print(first, middle, last, a, b, c, d, e, f, g, h, i) if __name__ == '__main__': main()	package main import ( "fmt" "strings" ) func main() { name := "Michael Wayne Phelps" first, middle, last := func(s []string) (string, string, string) { return s[0], s[1], s[2] }(strings.Fields(name)) x := []int{1, 2, 3} a, b, c := x[0], x[1], x[2] d, e, f := 4, 5, 6 g, h, i := 7, 8, 9 fmt.Println(first, middle, last, a, b, c, d, e, f, g, h, i) }

cast_to_float

Python

Go

def main(): num1 = input('Enter first number: ') num2 = input('Enter second number: ') sum = float(num1) + float(num2) print("The sum of", num1, "and", num2, "is", sum) if __name__ == '__main__': main()

package main import ( "bufio" "fmt" "os" "strconv" "strings" ) func main() { num1 := func(msg string) string { fmt.Print(msg) text, _ := bufio.NewReader(os.Stdin).ReadString('\n') return strings.ReplaceAll(text, "\n", "") }("Enter first number: ") num2 := func(msg string) string { fmt.Print(msg) text, _ := bufio.NewReader(os.Stdin).ReadString('\n') return strings.ReplaceAll(text, "\n", "") }("Enter second number: ") sum := func() float64 { i, err := strconv.ParseFloat(num1, 64) if err != nil { panic(err) } return i }() + func() float64 { i, err := strconv.ParseFloat(num2, 64) if err != nil { panic(err) } return i }() fmt.Println("The sum of", num1, "and", num2, "is", sum) }

jsondump

Python

Go

import json import random def main(): print(json.dumps(1)) print(json.dumps("hello")) c = json.dumps({"hello": 1, "how": "are you"}) print(c + c) print(json.dumps([1, 2, 3])) if __name__ == '__main__': main()

package main import ( "encoding/json" "fmt" ) func main() { fmt.Println(func() string { b, err := json.Marshal(1) if err != nil { panic(err) } return string(b) }()) fmt.Println(func() string { b, err := json.Marshal("hello") if err != nil { panic(err) } return string(b) }()) c := func() string { b, err := json.Marshal(map[string]interface{}{"hello": 1, "how": "are you"}) if err != nil { panic(err) } return string(b) }() fmt.Println(c + c) fmt.Println(func() string { b, err := json.Marshal([]int{1, 2, 3}) if err != nil { panic(err) } return string(b) }()) }

strdunder

Python	Go
class A: a: str def __init__(self, val): self.a = val def __str__(self): return self.a def main(): val = A("ok") print(val) if __name__ == '__main__': main()	package main import "fmt" type A struct { a string } func NewA(val string) (self *A) { self = new(A) self.a = val return } func (self *A) String() string { return self.a } func main() { val := NewA("ok") fmt.Println(val) }

globfiles

Python

Go

import glob def main(): for py_file in glob.glob("./*.py"): print("=" * 20, py_file, "=" * 20) with open(py_file) as py_f: for line in py_f: print(line.rstrip()) if __name__ == '__main__': main()

package main import ( "bufio" "fmt" "io" "os" "path/filepath" "strings" "unicode" ) func main() { for _, py_file := range func(pattern string) []string { matches, err := filepath.Glob(pattern) if err != nil { panic(err) } return matches }("./*.py") { fmt.Println(strings.Repeat("=", 20), py_file, strings.Repeat("=", 20)) func() { py_f := func() *os.File { f, err := os.OpenFile(py_file, os.O_RDONLY, 0o777) if err != nil { panic(err) } return f }() defer func() { if err := py_f.Close(); err != nil { panic(err) } }() if sc, line, err := bufio.NewReader(py_f), "", *new(error); true { for { line, err = sc.ReadString('\n') if err != nil && (err == io.EOF && len(line) == 0 || err != io.EOF) { break } fmt.Println(strings.TrimRightFunc(line, unicode.IsSpace)) } if err != io.EOF { panic(err) } } }() } }

stringmultiply

Python

Go

def main(): s = "1, 2, 3, 4" x = s * 5 y = str({1, 2, 3, 4}) * 6 z = str([1, 2, 3, 4]) * 7 a = str({1: 2, 3: 4}) * 8 b = str((1, 2, 3, 4)) * 9 c = "1, 2, 3, 4" * 10 d = " 1, 2, 3, 4 ".strip() * 11 print(x, y, z, a, b, c, d) if __name__ == '__main__': main()

package main import ( "fmt" "strings" ) func main() { s := "1, 2, 3, 4" x := strings.Repeat(s, 5) y := strings.Repeat(fmt.Sprintf("%v", map[interface{}]struct{}{1: {}, 2: {}, 3: {}, 4: {}}), 6) z := strings.Repeat(fmt.Sprintf("%v", []int{1, 2, 3, 4}), 7) a := strings.Repeat(fmt.Sprintf("%v", map[interface{}]interface{}{1: 2, 3: 4}), 8) b := strings.Repeat(fmt.Sprintf("%v", [4]int{1, 2, 3, 4}), 9) c := strings.Repeat("1, 2, 3, 4", 10) d := strings.Repeat(strings.TrimSpace(" 1, 2, 3, 4 "), 11) fmt.Println(x, y, z, a, b, c, d) }

scope

Python	Go
import random def main(): if random.random() > 0.5: a = 1 else: a = 2 if random.random() > 0.5: if random.random() > 0.5: b = 1 else: b = 2 else: b = 3 def hello_world(): c = 3 print(c) hello_world() print(a, b) if __name__ == '__main__': main()	package main import ( "fmt" "math/rand" "time" ) func init() { rand.Seed(time.Now().UnixNano()) } func main() { var a int var b int if rand.Float64() > 0.5 { a = 1 } else { a = 2 } if rand.Float64() > 0.5 { if rand.Float64() > 0.5 { b = 1 } else { b = 2 } } else { b = 3 } hello_world := func() { c := 3 fmt.Println(c) } hello_world() fmt.Println(a, b) }

forelse

Python

Go

def main(): for x in range(4): if x == 5: break else: print("Well of course that didn't happen") for x in range(7): if x == 5: break else: print("H-hey wait!") i = 0 while i < 3: print("Works with while too") for x in range(3): print("BTW don't worry about nested breaks") break if i == 10: break i += 1 else: print("Yeah not likely") print(i) if __name__ == '__main__': main()

package main import "fmt" func main() { var x int if func() bool { for x = 0; x < 4; x++ { if x == 5 { return false } } return true }() { fmt.Println("Well of course that didn't happen") } if func() bool { for x = 0; x < 7; x++ { if x == 5 { return false } } return true }() { fmt.Println("H-hey wait!") } i := 0 if func() bool { for i < 3 { fmt.Println("Works with while too") for x = 0; x < 3; x++ { fmt.Println("BTW don't worry about nested breaks") break } if i == 10 { return false } i += 1 } return true }() { fmt.Println("Yeah not likely") } fmt.Println(i) }

slicemultiply

Python

Go

def main(): n = 3 x = [1, 2, 3] * n x = x * 3 x *= 3 print(len(x), x) if __name__ == '__main__': main()

package main import "fmt" func main() { n := 3 x := func(repeated []int, n int) (result []int) { for i := 0; i < n; i++ { result = append(result, repeated...) } return result }([]int{1, 2, 3}, n) x = func(repeated []int, n int) (result []int) { for i := 0; i < n; i++ { result = append(result, repeated...) } return result }(x, 3) x = func(repeated []int, n int) (result []int) { for i := 0; i < n; i++ { result = append(result, repeated...) } return result }(x, 3) fmt.Println(len(x), x) }

printend

Python	Go
def fib(n): a, b = 0, 1 while a < n: print(a, end=' ') a, b = b, a + b print() def main(): fib(1000) print("All done!", end='') if __name__ == '__main__': main()	package main import "fmt" func fib(n int) { a, b := 0, 1 for a < int(n) { fmt.Print(a, " ") a, b = b, a+b } fmt.Println() } func main() { fib(1000) fmt.Print("All done!") }

structdunders

Python

Go

class Number: def __init__(self, x): self.x = x def __add__(self, other: 'Number'): return Number(self.x + other.x) def __mul__(self, other: 'Number'): return Number(self.x * other.x) def __str__(self): return str(self.x) class ComplexNumber: def __init__(self, real, imag): self.real = real self.imag = imag def __str__(self): return str(self.real) + "+" + str(self.imag) + "i" def main(): five = Number(5) six = Number(6) eleven = five + six print(eleven) fifty_five = eleven * five print(fifty_five) i = ComplexNumber(Number(0), Number(-1)) n = ComplexNumber(Number(3), Number(-6)) print(i, n) if __name__ == '__main__': main()

package main import "fmt" type Number struct { x int } func NewNumber(x int) (self *Number) { self = new(Number) self.x = x return } func (self *Number) Add(other Number) *Number { return NewNumber(self.x + other.x) } func (self *Number) Mul(other Number) *Number { return NewNumber(self.x * other.x) } func (self *Number) String() string { return fmt.Sprintf("%v", self.x) } type ComplexNumber struct { real *Number imag *Number } func NewComplexNumber(real *Number, imag *Number) (self *ComplexNumber) { self = new(ComplexNumber) self.real = real self.imag = imag return } func (self *ComplexNumber) String() string { return fmt.Sprintf("%v", self.real) + "+" + fmt.Sprintf("%v", self.imag) + "i" } func main() { five := NewNumber(5) six := NewNumber(6) eleven := five.Add(*six) fmt.Println(eleven) fifty_five := five.Mul(*eleven) fmt.Println(fifty_five) i := NewComplexNumber(NewNumber(0), NewNumber(-1)) n := NewComplexNumber(NewNumber(3), NewNumber(-6)) fmt.Println(i, n) }

algomajorityelement

Python	Go
def majorityElement(nums: list[int]) -> int: element, cnt = 0, 0 for e in nums: if element == e: cnt += 1 elif cnt == 0: element, cnt = e, 1 else: cnt -= 1 return element def main(): print(majorityElement([3,2,3])) # 3 print(majorityElement([2,2,1,1,1,2,2])) # 2 if __name__ == '__main__': main()	package main import "fmt" func majorityElement(nums []int) int { element, cnt := 0, 0 for _, e := range nums { if element == e { cnt += 1 } else if cnt == 0 { element, cnt = e, 1 } else { cnt -= 1 } } return element } func main() { fmt.Println(majorityElement([]int{3, 2, 3})) fmt.Println(majorityElement([]int{2, 2, 1, 1, 1, 2, 2})) }

algobisection

Python

Go

def bisection(function, a: float, b: float) -> float: start = a end = b if function(a) == 0: # one of the a or b is a root for the function return a elif function(b) == 0: return b elif ( function(a) * function(b) > 0 ): # if none of these are root and they are both positive or negative, raise ValueError("could not find root in given interval.") else: mid = start + (end - start) / 2.0 while abs(start - mid) > 10 ** -7: # until precisely equals to 10^-7 if function(mid) == 0: return mid elif function(mid) * function(start) < 0: end = mid else: start = mid mid = start + (end - start) / 2.0 return mid def f(x: float): return x ** 3 - 2 * x - 5 def main(): print(bisection(f, 1, 1000))

package main import ( "fmt" "math" ) func bisection(function func(x float64) float64, a float64, b float64) float64 { start := a end := b if function(a) == 0 { return a } else if function(b) == 0 { return b } else if function(a)*function(b) > 0 { panic(fmt.Errorf("ValueError: %v", "could not find root in given interval.")) } else { mid := start + (end-start)/2.0 for math.Abs(start-mid) > math.Pow(10, -7) { if function(mid) == 0 { return mid } else if function(mid)*function(start) < 0 { end = mid } else { start = mid } mid = start + (end-start)/2.0 } return mid } } func f(x float64) float64 { return math.Pow(x, 3) - float64(2*x) - 5 } func main() { fmt.Println(bisection(f, 1, 1000)) }

algointersection

Python

Go

import math def intersection(function, x0: float, x1: float) -> float: x_n = x0 x_n1 = x1 while True: if x_n == x_n1 or function(x_n1) == function(x_n): raise ZeroDivisionError("float division by zero, could not find root") x_n2 = x_n1 - ( function(x_n1) / ((function(x_n1) - function(x_n)) / (x_n1 - x_n)) ) if abs(x_n2 - x_n1) < 10 ** -5: return x_n2 x_n = x_n1 x_n1 = x_n2 def f(x: float) -> float: return math.pow(x, 3) - (2 * x) - 5 def main(): print(intersection(f, 3, 3.5)) if __name__ == '__main__': main()

package main import ( "fmt" "math" ) func intersection(function func(x float64) float64, x0 float64, x1 float64) float64 { x_n := x0 x_n1 := x1 for { if x_n == x_n1 || function(x_n1) == function(x_n) { panic( fmt.Errorf("ZeroDivisionError: %v", "float division by zero, could not find root"), ) } x_n2 := x_n1 - function(x_n1)/((function(x_n1)-function(x_n))/(x_n1-x_n)) if math.Abs(x_n2-x_n1) < math.Pow(10, -5) { return x_n2 } x_n = x_n1 x_n1 = x_n2 } } func f(x float64) float64 { return math.Pow(x, 3) - float64(2*x) - 5 } func main() { fmt.Println(intersection(f, 3, 3.5)) }

bitwisenot

Python	Go
def main(): yeah = 9 yeah &= ~0x3 print(yeah) if __name__ == '__main__': main()	package main import "fmt" func main() { yeah := 9 yeah &= ^3 fmt.Println(yeah) }

index

Python	Go
def main(): x = [1, 2, 3, 7, 3] print(x.index(7)) if __name__ == '__main__': main()	package main import ( "errors" "fmt" ) func main() { x := []int{1, 2, 3, 7, 3} fmt.Println(func() int { for i, val := range x { if val == 7 { return i } } panic(errors.New("ValueError")) }()) }

timecode

Python	Go
import time def main(): print(time.time()) print(time.time_ns()) print(time.ctime(time.time())) print(time.ctime(1000000000)) if __name__ == '__main__': main()	package main import ( "fmt" "time" ) func main() { fmt.Println(float64(time.Now().UnixNano()) / 1000000000.0) fmt.Println(time.Now().UnixNano()) fmt.Println(time.Now().Format("Mon Jan 02 15:04:05 2006")) fmt.Println(time.Unix(1000000000, 0).Format("Mon Jan 02 15:04:05 2006")) }

typecall

Python

Go

class Custom1: def __init__(self): pass class Custom2: def __init__(self, x): self.x = x def main(): b = False i = 12 f = 4.2 s = "bla bla" sb = b"bla bla" s1 = {1, 2, 3} s2 = {"a", "b", "c"} d1 = {"hi": 1} d2 = {"hi": "hi"} l1 = [1, 2, 3] l2 = ["a", "b", "c"] t1 = (1, 2, 3) t2 = (1, 2) c1 = Custom1() c2 = Custom2(1) c3 = Custom2(2) fx = lambda x: print(x) fxy = lambda x, y: print(x, y) print("type(b) =", type(b)) print("type(i) =", type(i)) print("type(f) =", type(f)) print("type(s) =", type(s)) print("type(sb) =", type(sb)) print("type(d1) =", type(d1)) print("type(d2) =", type(d2)) print("type(l1) =", type(l1)) print("type(l2) =", type(l2)) print("type(t1) =", type(t1)) print("type(t2) =", type(t2)) print("type(c1) =", type(c1)) print("type(c2) =", type(c2)) print("type(s1) =", type(s1)) print("type(s2) =", type(s2)) print("type(c3) =", type(c3)) print("type(fx) =", type(fx)) print("type(fxy) =", type(fxy)) print("type(d1) == type(d2)?", type(d1) == type(d2)) print("type(l1) == type(l2)?", type(l1) == type(l2)) print("type(t1) == type(t2)?", type(t1) == type(t2)) print("type(l1) == type(t1)?", type(l1) == type(t1)) print("type(c1) == type(c2)?", type(c1) == type(c2)) print("type(c2) == type(c3)?", type(c2) == type(c3)) print("type(fx) == type(fxy)?", type(fx) == type(fxy)) print("type(s) == str?", type(s) == str) print("type(sb) == bytes?", type(sb) == bytes) print("type(i) == int?", type(i) == int) print("type(f) == float?", type(f) == float) print("type(l1) == list?", type(l1) == list) print("type(t1) == tuple?", type(t1) == tuple) print("type(s1) == type(s2)?", type(s1) == type(s2)) print("type(c1) == Custom1", type(c1) == Custom1) print("type(c2) == Custom2", type(c2) == Custom2) print("type(c2) == Custom1", type(c2) == Custom1) if __name__ == '__main__': main()

package main import ( "fmt" "reflect" ) type Custom1 struct{} func NewCustom1() (self *Custom1) { self = new(Custom1) return } type Custom2 struct { x int } func NewCustom2(x int) (self *Custom2) { self = new(Custom2) self.x = x return } func main() { b := false i := 12 f := 4.2 s := "bla bla" sb := []byte("bla bla") s1 := map[int]struct{}{1: {}, 2: {}, 3: {}} s2 := map[string]struct{}{"a": {}, "b": {}, "c": {}} d1 := map[string]int{"hi": 1} d2 := map[string]string{"hi": "hi"} l1 := []int{1, 2, 3} l2 := []string{"a", "b", "c"} t1 := [3]int{1, 2, 3} t2 := [2]int{1, 2} c1 := NewCustom1() c2 := NewCustom2(1) c3 := NewCustom2(2) fx := func(x interface{}) { fmt.Println(x) } fxy := func(x interface{}, y interface{}) { fmt.Println(x, y) } fmt.Println("type(b) =", reflect.TypeOf(b)) fmt.Println("type(i) =", reflect.TypeOf(i)) fmt.Println("type(f) =", reflect.TypeOf(f)) fmt.Println("type(s) =", reflect.TypeOf(s)) fmt.Println("type(sb) =", reflect.TypeOf(sb)) fmt.Println("type(d1) =", reflect.TypeOf(d1)) fmt.Println("type(d2) =", reflect.TypeOf(d2)) fmt.Println("type(l1) =", reflect.TypeOf(l1)) fmt.Println("type(l2) =", reflect.TypeOf(l2)) fmt.Println("type(t1) =", reflect.TypeOf(t1)) fmt.Println("type(t2) =", reflect.TypeOf(t2)) fmt.Println("type(c1) =", reflect.TypeOf(c1)) fmt.Println("type(c2) =", reflect.TypeOf(c2)) fmt.Println("type(s1) =", reflect.TypeOf(s1)) fmt.Println("type(s2) =", reflect.TypeOf(s2)) fmt.Println("type(c3) =", reflect.TypeOf(c3)) fmt.Println("type(fx) =", reflect.TypeOf(fx)) fmt.Println("type(fxy) =", reflect.TypeOf(fxy)) fmt.Println("type(d1) == type(d2)?", reflect.TypeOf(d1).Kind() == reflect.TypeOf(d2).Kind()) fmt.Println("type(l1) == type(l2)?", reflect.TypeOf(l1).Kind() == reflect.TypeOf(l2).Kind()) fmt.Println("type(t1) == type(t2)?", reflect.TypeOf(t1).Kind() == reflect.TypeOf(t2).Kind()) fmt.Println("type(l1) == type(t1)?", reflect.TypeOf(l1).Kind() == reflect.TypeOf(t1).Kind()) fmt.Println("type(c1) == type(c2)?", reflect.TypeOf(c1) == reflect.TypeOf(c2)) fmt.Println("type(c2) == type(c3)?", reflect.TypeOf(c2) == reflect.TypeOf(c3)) fmt.Println("type(fx) == type(fxy)?", reflect.TypeOf(fx).Kind() == reflect.TypeOf(fxy).Kind()) fmt.Println("type(s) == str?", reflect.TypeOf(s).Kind() == reflect.String) fmt.Println("type(sb) == bytes?", reflect.TypeOf(sb).Kind() == reflect.Slice) fmt.Println("type(i) == int?", reflect.TypeOf(i).Kind() == reflect.Int) fmt.Println("type(f) == float?", reflect.TypeOf(f).Kind() == reflect.Float64) fmt.Println("type(l1) == list?", reflect.TypeOf(l1).Kind() == reflect.Slice) fmt.Println("type(t1) == tuple?", reflect.TypeOf(t1).Kind() == reflect.Array) fmt.Println("type(s1) == type(s2)?", reflect.TypeOf(s1).Kind() == reflect.TypeOf(s2).Kind()) fmt.Println("type(c1) == Custom1", reflect.TypeOf(c1) == reflect.TypeOf(new(Custom1))) fmt.Println("type(c2) == Custom2", reflect.TypeOf(c2) == reflect.TypeOf(new(Custom2))) fmt.Println("type(c2) == Custom1", reflect.TypeOf(c2) == reflect.TypeOf(new(Custom1))) }

TODOs

Some things I'd like to add soon...

• "value in range(start, stop, step)" => a conditional statement
• Exhaustive implementation of list/dict/int/float/bytes methods