Python – Custom space size padding in Strings List

In this article given a Strings List, the task is to write a Python program to pad each string with spaces with specified leading and trailing number of spaces required.

Examples:

Input: test_list = [“Gfg”, “is”, “Best”], lead_size = 3, trail_size = 2

Output: [‘   Gfg  ‘, ‘   is  ‘, ‘   Best  ‘]

Explanation: Each word starts after 3 spaces and add 2 spaces after completion.

Input: test_list = [“Gfg”, “Best”], lead_size = 3, trail_size = 2

Output: [‘   Gfg  ‘, ‘   Best  ‘]

Explanation: Each word starts after 3 spaces and add 2 spaces after completion.

Method #1: Using loop

In this, we perform the task of adding trailing and leading required spaces using loop. The * operator is used to get required number of spaces.

Python3

# Python3 code to demonstrate working of
# Custom space size padding in Strings List
# Using loop

# initializing lists
test_list = ["Gfg", "is", "Best"]

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

# initializing padding numbers
lead_size = 3
trail_size = 2

res = []
for ele in test_list:

    # * operator handles number of spaces
    res.append((lead_size * ' ') + ele + (trail_size * ' '))

# printing result
print("Padded Strings : " + str(res))

Output:

The original list is : ['Gfg', 'is', 'Best']
Padded Strings : ['   Gfg  ', '   is  ', '   Best  ']

Method #2: Using list comprehension

Similar way as above, the only difference being the use of list comprehension as a one-liner alternative to solve problems.

Python3

# Python3 code to demonstrate working of
# Custom space size padding in Strings List
# Using list comprehension

# initializing lists
test_list = ["Gfg", "is", "Best"]

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

# initializing padding numbers
lead_size = 3
trail_size = 2

# using list comprehension for one liner alternative
res = [(lead_size * ' ') + ele + (trail_size * ' ') for ele in test_list]

# printing result
print("Padded Strings : " + str(res))

Output:

The original list is : ['Gfg', 'is', 'Best']
Padded Strings : ['   Gfg  ', '   is  ', '   Best  ']

The time and space complexity for all the methods are the same:

Time Complexity: O(n)

Space Complexity: O(n)