Python | Search for strings with a given substring in a list

Python Methods and Functions | Regular Expressions | String Variables

Let's discuss some ways to find strings with a given substring in a list.

Method # 1: Using List Comprehension
List Comprehension — it is an elegant way to accomplish any specific task because it improves readability in the long run. This task can be accomplished using a naive method and hence can be reduced to list comprehension.

# Python code for demonstration
# find substring strings
# use comprehension list

  
# initializing list

test_list = [ 'GeeksforGeeks' , 'Geeky' , ' Computers' , ' Algorithms' ]

  
# print original linen list

print ( "The original list is: " + str (test_list))

 
# substring initialization

subs = 'Geek'

  
# use comprehension list
# get substring string

res = [i for i in test_list if subs in i]

 
# print result

print ( "All strings with given substring are:" + str (res))

Exit:

 The original list is: ['GeeksforGeeks',' Geeky', 'Computers',' Algorithms' ] All strings with given substring are: ['GeeksforGeeks',' Geeky'] 

Method # 2: Using filter () + lambda
This function can also do this string search task with lambdas. It simply filters out all strings that match a specific substring and then adds it to a new list.

# Python code for demo
# find substring strings
# using the () + lambda filter

 
# initializing list

test_list = [ 'GeeksforGeeks' , 'Geeky' , ' Computers' , ' Algorithms' ]

 
# print the original with squeak

print ( "The original list is: " + str (test_list))

 
# substring initialization

subs = ' Geek'

 
# using the () + lambda filter
# get a substring string

res = list ( filter ( lambda x: subs in x, test_list))

  
# print result

print ( "All strings with given substring are:" + str (res))

Exit :

 The original list is: ['GeeksforGeeks',' Geeky', 'Computers',' Algorithms'] All strings with given substring are: ['GeeksforGeeks', 'Geeky'] 

Method # 3: Using re + search ()
Regular expressions can be used to accomplish many tasks in Python. Regular expressions can also come in handy for this particular task. It finds all matching substring with search () and returns the result.

# Python code for demonstration
# find substring strings
# using re + search ()

import re

 
# initializing list

test_list = [ 'GeeksforGeeks' , ' Geeky' , 'Computers' , ' Algorithms' ]

 
# print original list

print ( "The original list is:" + str (test_list))

 
# substring initialization

subs = 'Geek'

 
# using re + search ()
# get a substring string

res = [x for x in test_list if re.search (subs, x)]

  
# print result

print ( "All strings with given substring are:" + str (res))

Exit :

 The original list is: ['GeeksforGeeks',' Geeky', 'Computers',' Algorithms'] All strings with given substring are: [' GeeksforGeeks', 'Geeky'] 




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