extractDate.py

# write a program for extraction of all the dates mentioned in an input text file and the standardization of them to a unique format. 

# For example, your program should identify all the date expressions (highlighted in bold) in the following pieces of text that give details about India’s Independence day:
# Independence Day is celebrated annually on 15 August as a national holiday in India commemorating the nation's independence from the United Kingdom on 15 August 1947, the day when the provisions of the 1947 Indian Independence Act, which transferred legislative sovereignty to the Indian Constituent Assembly, came into effect. India retained King George VI as head of state until its transition to a republic, when the nation adopted the Constitution of India on 26 January 1950 (celebrated as Indian Republic Day) and replaced the dominion prefix, Dominion of India, with the enactment of the sovereign law Constitution of India. India attained independence following the Independence Movement noted for largely non-violent resistance and civil disobedience.
# It was on 15th August 1947 that India was declared independent from British colonialism, and the reins of control were handed over to the leaders of the Country.
# The Red Fort in Dehli is also an important Independence Day symbol in India as it is where Indian Prime Minister Jawahar Lal Nehru unveiled India's flag on August 15, 1947.
# At midnight between 14/08/1947 and 15/08/1947 free India's first prime minister Pandit Jawaharlal Nehru gave his famous "Tryst with Destiny" speech.


# For example, if your program identifies 14/08/1947 as a date then it should standardize it to 14-August-1947. If the identified date does not have an explicit year then the default year should be 2022. For example, in the following sentence year is not explicitly associated with 15 August. In such a case, your program should extract 15-August-2022 as the standardized date.
# Independence Day is celebrated annually on 15 August as a national holiday in India... Similarly, the default values for day and month are 01 and January respectively.
# You should write a date_extraction_rollno.py (you should properly document your code). It should take one text file as an input and produce and an XML file as an output (dates_rollno.xml). For the example text given above, your program should produce the following output:
# <output>
# Independence Day is celebrated annually on <date std_date=15-August-2022>15 August </date> as a national holiday in India commemorating the nation's independence from the United Kingdom on <date std_date=15-August-1947>15 August 1947 </date>, the day when the provisions of the 1947 Indian Independence Act, which transferred legislative sovereignty to the Indian Constituent Assembly, came into effect. India retained King George VI as head of state until its transition to a republic, when the nation adopted the Constitution of India on <date std_date=26-January-1950> 26 January 1950 </date>(celebrated as Indian Republic Day) and replaced the dominion prefix, Dominion of India, with the enactment of the sovereign law Constitution of India. India attained independence following the Independence Movement noted for largely non-violent resistance and civil disobedience.
# It was on <date std_date=15-August-1947>15th August 1947 </date> that India was declared independent from British colonialism, and the reins of control were handed over to the leaders of the Country.
# The Red Fort in Dehli is also an important Independence Day symbol in India as it is where Indian Prime Minister Jawahar Lal Nehru unveiled India's flag on <date std_date=15-August-1947>August 15, 1947 </date>.
# At midnight between <date std_date=14-August-1947>14/08/1947 </date> and <date std_date=15-August-1947>15/08/1947 </date> free India's first prime minister Pandit Jawaharlal Nehru gave his famous "Tryst with Destiny" speech.
# </output>
import re
import datetime
import xml.etree.ElementTree as ET
text = """
Independence Day is celebrated annually on 15 August as a national holiday in India commemorating the nation's independence from the United Kingdom on 15 August 1947, the day when the provisions of the 1947 Indian Independence Act, which transferred legislative sovereignty to the Indian Constituent Assembly, came into effect. India retained King George VI as head of state until its transition to a republic, when the nation adopted the Constitution of India on 26 January 1950 (celebrated as Indian Republic Day) and replaced the dominion prefix, Dominion of India, with the enactment of the sovereign law Constitution of India. India attained independence following the Independence Movement noted for largely non-violent resistance and civil disobedience.
It was on 15th August 1947 that India was declared independent from British colonialism, and the reins of control were handed over to the leaders of the Country.
The Red Fort in Dehli is also an important Independence Day symbol in India as it is where Indian Prime Minister Jawahar Lal Nehru unveiled India's flag on August 15, 1947.
At midnight between 14/08/1947 and 15/08/1947 free India's first prime minister Pandit Jawaharlal Nehru gave his famous "Tryst with Destiny" speech.
"""
output = ET.Element('output')
# extract all the dates mentioned in an input text file and the standardization of them to a unique format
def extractDate(text):
    # regex for extracting dates
    date_regex = re.compile(r'(\d{1,2}/\d{1,2}/\d{4})')
    # regex for extracting year
    year_regex = re.compile(r'(\d{4})')
    # regex for extracting month
    month_regex = re.compile(r'(\d{1,2})')
    # regex for extracting day
    day_regex = re.compile(r'(\d{1,2})')
    # regex for extracting month name
    month_name_regex = re.compile(r'(January|February|March|April|May|June|July|August|September|October|November|December)')
    
    # extract all the dates mentioned in an input text file
    dates = date_regex.findall(text)
    # extract all the year mentioned in an input text file
    years = year_regex.findall(text)
    # extract all the month mentioned in an input text file
    months = month_regex.findall(text)
    # extract all the day mentioned in an input text file
    days = day_regex.findall(text)
    # extract all the month name mentioned in an input text file
    month_names = month_name_regex.findall(text)

    # standardize the dates
    for date in dates:
        # extract the year
        year = years[dates.index(date)]
        # extract the month
        month = months[dates.index(date)]
        # extract the day
        day = days[dates.index(date)]
        # extract the month name
        month_name = month_names[dates.index(date)]
        # standardize the date
        std_date = str(day) + '-' + month_name + '-' + year
        # create an element for the date
        date_element = ET.Element('date', {'std_date':std_date})
        # append the date element to the output element
        output.append(date_element)
        # append the date to the date element
        date_element.text = date
    

    return output

output = extractDate(text)
# write the output to an XML file
tree = ET.ElementTree(output)
tree.write('dates_rollno.xml')