Python | Program that matches a word containing ‘g’ followed by one or more e’s using regex

Prerequisites : Regular Expressions | Set 1, Set 2 Given a string, the task is to check if that string contains any g followed by one or more e’s in it, otherwise, print No match. Examples :

Input : geeks for geeks
Output : geeks 
         geeks

Input : graphic era
Output : No match 

Approach : Firstly, make a regular expression (regex) object that matches a word which contains ‘g’ followed by one or more e’s, then pass a string in the findall method. This method returns the list of the matched strings. Loop through the list and print each matched word.

\w – represent Any letter, numeric digit, or the underscore character. * means zero or more occurrence of the character. + means one or more occurrence of the character.

Below is the implementation : 

Python3

# Python program that matches a word
# containing ‘g’ followed by one or
# more e’s using regex

# import re packages
import re

# Function check if the any word of
# the string containing 'g' followed
# by one or more e's
def check(string) :


    # Regex \w * ge+\w * will match
    # text that contains 'g', followed
    # by one or more 'e'
    regex = re.compile("ge+\w*")

    # The findall() method returns all
    # matching strings of the regex pattern
    match_object = regex.findall(string)

    # If length of match_object is not
    # equal to zero then it contains
    # matched string
    if len(match_object) != 0 :

        # looping through the list
        for word in match_object :
            print(word)

    else :
        print("No match")


# Driver Code
if __name__ == '__main__' :

    # Enter the string
    string = "Welcome to geeks for geeks"

    # Calling check function
    check(string)

Output :

geeks
geeks

Time complexity:  O(n) where n is the length of the input string
Auxiliary Space: O(1), as the program uses a constant amount of memory for the regex pattern and the match_object.