The compare_strings function is supposed to compare just the alphanumeric content

There is a problem in the given code in the following statement:

Problem:

punctuation = r"[.?!,;:-']"

This produces the following error:

Error:

bad character range

Fix:

The hyphen - should be placed at the start or end of punctuation characters. Here the role of hyphen is to determine the range of characters. Another way is to escape the hyphen - using using backslash \ symbol.

So the above statement becomes:

punctuation = r"[-.?!,;:']"  

You can also do this:

punctuation = r"[.?!,;:'-]"  

You can also change this statement as:

punctuation = r"[.?!,;:\-']"

Explanation:

The complete program is as follows. I have added a print statement print('string1:',string1,'\nstring2:',string2) that prints the string1 and string2 followed by return string1 == string2  which either returns true or false. However you can omit this print('string1:',string1,'\nstring2:',string2) statement and the output will just display either true or false

import re  #to use regular expressions

def compare_strings(string1, string2):  #function compare_strings that takes two strings as argument and compares them

   string1 = string1.lower().strip()  # converts the string1 characters to lowercase using lower() method and removes trailing blanks

   string2 = string2.lower().strip()  # converts the string1 characters to lowercase using lower() method and removes trailing blanks

   punctuation = r"[-.?!,;:']"  #regular expression for punctuation characters

   string1 = re.sub(punctuation, r"", string1)  # specifies RE pattern i.e. punctuation in the 1st argument, new string r in 2nd argument, and a string to be handle i.e. string1 in the 3rd argument

   string2 = re.sub(punctuation, r"", string2)  # same as above statement but works on string2 as 3rd argument

   print('string1:',string1,'\nstring2:',string2)  #prints both the strings separated with a new line

   return string1 == string2  # compares strings and returns true if they matched else false

#function calls to test the working of the above function compare_strings

print(compare_strings("Have a Great Day!","Have a great day?")) # True

print(compare_strings("It's raining again.","its raining, again")) # True

print(compare_strings("Learn to count: 1, 2, 3.","Learn to count: one, two, three.")) # False

print(compare_strings("They found some body.","They found somebody.")) # False

The screenshot of the program along with its output is attached.

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