Python | Extract Nth words in Strings List

Sometimes, while working while working with Python Lists, we can have problem in which we need to perform the task of extracting Nth word of each string in List. This can have application in web-development domain. Lets discuss certain ways in which this task can be performed. Method #1 : Using list comprehension + split() The combination of above methods can be used to solve this problem. In this, we perform the task of getting Nth word using split and recreate list using list comprehension. 

Python3

# Python3 code to demonstrate working of
# Extract Nth words in Strings List
# Using list comprehension + split()

# initializing list
test_list = ['Gfg best for', 'All geeks', 'It is for', 'all CS professionals']

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

# initializing N
N = 2

# Extract Nth words in Strings List
# Using list comprehension + split()
res = [sub.split()[N - 1] for sub in test_list if len(sub.split()) > 1]

# printing result
print("The Nth words in list are : " + str(res))

Output : 

The original list is : ['Gfg best for', 'All geeks', 'It is for', 'all CS professionals']
The Nth words in list are : ['best', 'geeks', 'is', 'CS']

Method #2 : Using list comprehension + enumerate() + split() The combination of above functions can be used to perform this task. In this, we use enumerate to check for the Nth word rather than split(). 

Python3

# Python3 code to demonstrate working of
# Extract Nth words in Strings List
# Using list comprehension + <code>enumerate() + split()

# initializing list
test_list = ['Gfg best for', 'All geeks', 'It is for', 'all CS professionals']

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

# initializing N
N = 2

# Extract Nth words in Strings List
# Using list comprehension + <code>enumerate() + split()
res = [ele for sub in test_list for idx, ele in enumerate(sub.split()) if idx == (N - 1)]

# printing result
print("The Nth words in list are : " + str(res))

Output : 

The original list is : ['Gfg best for', 'All geeks', 'It is for', 'all CS professionals']
The Nth words in list are : ['best', 'geeks', 'is', 'CS']

 Method #3 : Using for loop + append() + split() + indexing

Python3

# Python3 code to demonstrate working of
# Extract Nth words in Strings List
# Using append() and for loop

# initializing list
test_list = ['Gfg best for', 'All geeks', 'It is for', 'all CS professionals']

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

# initializing N
N = 2
res = []
for i in test_list:
    words = i.split()
    # Extract Nth words in Strings List
    res.append(words[N-1])


# printing result
print("The Nth words in list are : " + str(res))

Output

The original list is :['Gfg best for', 'All geeks', 'It is for', 'all CS professionals']
The Nth words in list are : ['best', 'geeks', 'is', 'CS']

Time Complexity: O(N*M)

Auxiliary Space: O(N*M)