import re
# Compile a regular expression pattern into a regular expression object, which can be used for matching using its match(), search() and other methods, described below.
prog = re.compile(pattern)
result = prog.match(string)
# is equivalent to
result = re.match(pattern, string)
import re
>>> m = re.search('(?<=abc)def', 'abcdef')
>>> m.group(0)
'def'
# Recursive Python3 program to find if a given pattern is
# present in a text
def exactMatch(text, pat, text_index, pat_index):
if text_index == len(text) and pat_index != len(pat):
return 0
# Else If last character of pattern reaches
if pat_index == len(pat):
return 1
if text[text_index] == pat[pat_index]:
return exactMatch(text, pat, text_index+1, pat_index+1)
return 0
# This function returns true if 'text' contain 'pat'
def contains(text, pat, text_index, pat_index):
# If last character of text reaches
if text_index == len(text):
return 0
# If current characters of pat and text match
if text[text_index] == pat[pat_index]:
if exactMatch(text, pat, text_index, pat_index):
return 1
else:
return contains(text, pat, text_index+1, pat_index)
# If current characters of pat and tex don't match
return contains(text , pat, text_index+1, pat_index)
# Driver program to test the above function
print(contains("geeksforgeeks", "geeks", 0, 0))
print(contains("geeksforgeeks", "geeksquiz", 0, 0))
print(contains("geeksquizgeeksquiz", "quiz", 0, 0))
# This code is contributed by ankush_953.