python how to use regex code example

Example 1: python regular expression

import re

# The string you want to find a pattern within
test_string = 'Hello greppers!'

# Creating a regular expression pattern
# This is a simple one which finds "Hello"
pattern = re.compile(r'Hello')

# This locates and returns all the occurences of the pattern
# within the test_string
match = pattern.finditer(test_string)

# Outputs all the ocurrences which were returned as 
# as match objects
for match in matches:
  print(match)

Example 2: re python3

import re
>>> m = re.search('(?<=abc)def', 'abcdef')
>>> m.group(0)
'def'

Example 3: regex in python

>>> import re
>>> p = re.compile('ab*')
>>> p
re.compile('ab*')