diff --git a/export/fortran/c_to_f.py b/export/fortran/c_to_f.py
index afce043cd..f724d14c7 100644
--- a/export/fortran/c_to_f.py
+++ b/export/fortran/c_to_f.py
@@ -8,10 +8,11 @@
 c_to_f.py <C input file> <Fortran output file> <C struct name(s)>
 '''
 
-import re, sys
+import re
+import sys
 
 def extract_c_struct_fields(c_code, struct_name):
-    struct_re = re.compile("^\s*typedef\s*struct\s*\{([^\}]*)\}\s*"+struct_name+"\s*;",re.MULTILINE | re.DOTALL)
+    struct_re = re.compile(r"^\s*typedef\s*struct\s*\{([^\}]*)\}\s*"+struct_name+r"\s*;",re.MULTILINE | re.DOTALL)
     m = struct_re.search(c_code)
     if not m: return []
     fields = m.group(1).splitlines()
@@ -26,7 +27,7 @@ def parse_c_struct_fields(fields):
     for f in fields:
         words = f.split()
         var = words.pop()
-        m = re.match("(\w*)(?:\[(\w+)\])?", var)
+        m = re.match(r"(\w*)(?:\[(\w+)\])?", var)
         name.append(m.group(1))
         size.append(m.group(2))
         dtype.append(' '.join(words))
@@ -77,4 +78,4 @@ def convert_type_c_to_f(dtype):
     f_out.write("end type\n")
 
 c_in.close()
-f_out.close()
\ No newline at end of file
+f_out.close()
diff --git a/export/fortran/make_defs.py b/export/fortran/make_defs.py
index 12ecfd176..55032f507 100644
--- a/export/fortran/make_defs.py
+++ b/export/fortran/make_defs.py
@@ -1,4 +1,5 @@
-import re, sys
+import re
+import sys
 f_in = open(sys.argv[1], 'r')
 f_out = open(sys.argv[2], 'w')
 for line in f_in:
diff --git a/python/setup.py.in b/python/setup.py.in
index 8f1b242e6..406f6218b 100644
--- a/python/setup.py.in
+++ b/python/setup.py.in
@@ -1,7 +1,8 @@
 import setuptools
 from setuptools import setup, Extension
 from setuptools.command.build_ext import build_ext
-import os, subprocess
+import os
+import subprocess
 
 # sources+tests
 os.sys.path.append("@PROJECT_SOURCE_DIR@")
diff --git a/tests/hartree-fock/hartree-fock++-validate.py b/tests/hartree-fock/hartree-fock++-validate.py
index d895a450e..857e8fd13 100644
--- a/tests/hartree-fock/hartree-fock++-validate.py
+++ b/tests/hartree-fock/hartree-fock++-validate.py
@@ -1,10 +1,13 @@
 from __future__ import print_function
-import sys, re, math, os
+import math
+import os
+import re
+import sys
 
 def pat_numbers(n):
     result = ''
     for i in range(n):
-        result += '\s*([+-e\d.]+)'
+        result += r'\s*([+-e\d.]+)'
     return result
 
 def validate(label, data, refdata, tolerance, textline):
@@ -107,21 +110,21 @@ def validate(label, data, refdata, tolerance, textline):
 Hok = False if LIBINT_ONEBODY_DERIV>1 and LIBINT_ERI_DERIV>1 else True
 
 for line in instr:
-    match1 = re.match('\*\* Hartree-Fock energy =' + pat_numbers(1), line)
-    match2 = re.match('\*\* edipole =' + pat_numbers(3), line)
-    match3 = re.match('\*\* equadrupole =' + pat_numbers(6), line)
-    match4 = re.match('\*\* 1-body forces =' + pat_numbers(9), line)
-    match5 = re.match('\*\* Pulay forces =' + pat_numbers(9), line)
-    match6 = re.match('\*\* 2-body forces =' + pat_numbers(9), line)
-    match7 = re.match('\*\* nuclear repulsion forces =' + pat_numbers(9), line)
-    match8 = re.match('\*\* Hartree-Fock forces =' + pat_numbers(9), line)
-    match9 = re.match('\*\* 1-body hessian =' + pat_numbers(45), line)
-    match10 = re.match('\*\* Pulay hessian =' + pat_numbers(45), line)
-    match11 = re.match('\*\* 2-body hessian =' + pat_numbers(45), line)
-    match12 = re.match('\*\* nuclear repulsion hessian =' + pat_numbers(45), line)
-    match13 = re.match('\*\* Hartree-Fock hessian =' + pat_numbers(45), line)
-    match14 = re.match('\*\* sph edipole =' + pat_numbers(3), line)
-    match15 = re.match('\*\* sph equadrupole =' + pat_numbers(5), line)
+    match1 = re.match(r'\*\* Hartree-Fock energy =' + pat_numbers(1), line)
+    match2 = re.match(r'\*\* edipole =' + pat_numbers(3), line)
+    match3 = re.match(r'\*\* equadrupole =' + pat_numbers(6), line)
+    match4 = re.match(r'\*\* 1-body forces =' + pat_numbers(9), line)
+    match5 = re.match(r'\*\* Pulay forces =' + pat_numbers(9), line)
+    match6 = re.match(r'\*\* 2-body forces =' + pat_numbers(9), line)
+    match7 = re.match(r'\*\* nuclear repulsion forces =' + pat_numbers(9), line)
+    match8 = re.match(r'\*\* Hartree-Fock forces =' + pat_numbers(9), line)
+    match9 = re.match(r'\*\* 1-body hessian =' + pat_numbers(45), line)
+    match10 = re.match(r'\*\* Pulay hessian =' + pat_numbers(45), line)
+    match11 = re.match(r'\*\* 2-body hessian =' + pat_numbers(45), line)
+    match12 = re.match(r'\*\* nuclear repulsion hessian =' + pat_numbers(45), line)
+    match13 = re.match(r'\*\* Hartree-Fock hessian =' + pat_numbers(45), line)
+    match14 = re.match(r'\*\* sph edipole =' + pat_numbers(3), line)
+    match15 = re.match(r'\*\* sph equadrupole =' + pat_numbers(5), line)
     if match1:
         eok = validate("HF energy", match1.groups(), eref, etol, line)
     elif match2:
diff --git a/tests/hartree-fock/hartree-fock-validate.py b/tests/hartree-fock/hartree-fock-validate.py
index d771fb6b8..c89c9513d 100644
--- a/tests/hartree-fock/hartree-fock-validate.py
+++ b/tests/hartree-fock/hartree-fock-validate.py
@@ -1,5 +1,7 @@
 from __future__ import print_function
-import sys, re, math
+import math
+import re
+import sys
 
 # first arg is the input file, if missing read sys.stdin
 try:
@@ -14,7 +16,7 @@
 returncode = 1
 for line in instr:
     print(line,end="")
-    x = re.match('\*\* Hartree-Fock energy =\s*([-\d.]+)', line)
+    x = re.match(r'\*\* Hartree-Fock energy =\s*([-\d.]+)', line)
     if x:
         efound_str = x.group(1)
         if (math.fabs(eref - float(efound_str)) < tol):
@@ -24,4 +26,4 @@
 if len(sys.argv) > 1:
     instr.close()
 
-sys.exit(returncode)
\ No newline at end of file
+sys.exit(returncode)