#Python's usage of regular expressions

In Python, regular expressions are used via the re module. Since regular expressions have their own escape syntax, it’s common to use Python raw strings to avoid double escaping.

#Pattern Matching

import re

# Validate email format
email_pattern = r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$'
if re.match(email_pattern, "user@example.com"):
    print("Valid email")
Run Code
>>> Establishing WebAssembly Runtime. 
>>> Standby. 
Powered by Shift.

#Text Search

import re

text = "Order ID: 12345, Date: 2023-08-15"
match = re.search(r'Order ID: (\d+), Date: (\d{4}-\d{2}-\d{2})', text)
if match:
    print(0, match.group(0))
    print(1, match.group(1))
    print(2, match.group(2))
Run Code
>>> Establishing WebAssembly Runtime. 
>>> Standby. 
Powered by Shift.

#Text Replacement

import re

text = "Username: user Password: 123456"
hidden = re.sub(r'\d{6}', '******', text)
print(hidden)
Run Code
>>> Establishing WebAssembly Runtime. 
>>> Standby. 
Powered by Shift.

#Text Splitting

import re

data = "Apple, Banana, Orange, Grape"
fruits = re.split(r',\s*', data)  # Split by comma, allowing optional space after
print(fruits)  # Output: ['Apple', 'Banana', 'Orange', 'Grape']
Run Code
>>> Establishing WebAssembly Runtime. 
>>> Standby. 
Powered by Shift.

#Compiling Regular Expressions

Compiling a pattern improves efficiency when used multiple times.

import re

# Compile email pattern
email_pattern = re.compile(r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$')
if email_pattern.match("user@example.com"):
    print("Valid email")
Run Code
>>> Establishing WebAssembly Runtime. 
>>> Standby. 
Powered by Shift.