Python Programs For Most Commonly Used Regex - 2024

So guys in this blog we will see the Python Programs for most commonly used regex like regex to check mobile phones, regex to check email, and many more. So without any further due, let’s do it…

Table of Contents

Most commonly used Regex codes

Regular Expressions	Description
foo.*	# Matches any string starting with foo
\d*	# Match any number of decimal digits
[a-zA-Z]+	# Match a sequence of one or more letters
text	Match literal text
.	Match any character except newline
^	Match the start of a string
$	Match the end of a string
*	Match 0 or more repetitions
+	Match 1 or more repetitions
?	Match 0 or 1 repetition
+?	Match 1 or more, as few as possible
*?	Match 0 or more, as few as possible
{m,n}	Match m to n repetitions
{m,n}?	Match m to n repetitions, few as possible
[…]	Match a set of characters
[^…]	Match characters, not in a set
A \| B	Match A or B (…) Match regex in parenthesis as a group
\number	Matches text matched by the previous group
\A	Matches start of the string
\b	Matches empty string at beginning or end of the word
\B	Matches empty string not at begin or end of the word
\d	Matches any decimal digit
\D	Matches any non-digit
\s	Matches any whitespace
\S	Matches any non-whitespace
\w	Matches any alphanumeric character
\W	Matches characters not in
\w \Z	Match at end of the string.
\\	Literal backslash

What is the regex to check a 10-digit mobile phone?

# Python Programs for Most commonly used Regex
# Regex to check a 10-digit mobile phone

import re

regex_expression = "[6-9][0-9]{9}"

mobile = input('Enter a mobile number - ')

if len(mobile)==10:
    m = re.fullmatch(regex_expression ,mobile)
    if m!=None:
        print('Valid 10 digit number')
    else:
        print('Not a valid 10 digit number')
else:
    print('Please enter a 10 digit mobile number')

The regex says that the number should start from either 6,7,8 or 9.
And then after that, there should be 9 numbers from the range (0,9).

Output

Enter a mobile number – 9999999999
Valid 10 digit number

Enter a mobile number – 1999999999
Not a valid 10 digit number

Enter a mobile number – 99999
Not a valid 10 digit number

What is the regex to check valid email?

# Python Programs for Most commonly used Regex
# Regex to check valid email format

import re

regex_expression = "[a-z0-9]+[\._]?[a-z0-9]+[@]\w+[.]\w{2,3}"

email = input('Enter an email id - ')

e = re.fullmatch(regex_expression ,email)

if e!=None:
    print('Valid email')
else:
    print('Not a valid email')

Output

Enter an email id – asharma@gmail.com
Valid email

Enter an email id – ..@gmail.com
Not a valid email

Enter an email id – asharma123@gmail.com
Valid email

What is the regex to check the date?

# Python Programs for Most commonly used Regex\
# Regex to check the date

import re

regex_expression = "\d{2}/\d{2}/\d{4}"

date = input('Enter a date - ')

e = re.fullmatch(regex_expression ,date)

if e!=None:
    print('Valid date')
else:
    print('Not a valid date')