Python Program to Remove All Whitespace from String

You can remove all whitespace from a string in Python using ''.join(s.split()), which splits the string by whitespace and joins it back without spaces.

Examples

Inputhello world

Outputhelloworld

Input Python is fun

OutputPythonisfun

Input

Output

How to Think About It

To remove all whitespace, think of breaking the string into parts wherever there is space, then putting those parts back together without any spaces. This way, all spaces, tabs, or newlines are removed.

Algorithm

1

Get the input string.

2

Split the string into parts using whitespace as separator.

3

Join all parts together without any spaces.

4

Return or print the joined string.

Code

python

s = input('Enter a string: ')
result = ''.join(s.split())
print(result)

Output

Enter a string: Python is fun
Pythonisfun

Dry Run

Let's trace the input ' Python is fun ' through the code

1

Input string

' Python is fun '

2

Split string by whitespace

['Python', 'is', 'fun']

3

Join parts without spaces

'Pythonisfun'

4

Print result

Pythonisfun

Step	Operation	Value
1	Input string	' Python is fun '
2	Split by whitespace	['Python', 'is', 'fun']
3	Join parts	'Pythonisfun'
4	Output	Pythonisfun

Why This Works

Step 1: Splitting the string

Using split() without arguments breaks the string at all whitespace, including spaces, tabs, and newlines.

Step 2: Joining without spaces

Using ''.join() combines the list of words back into one string without adding any spaces.

Alternative Approaches

Using replace() method

python

s = input('Enter a string: ')
result = s.replace(' ', '')
print(result)

This removes only space characters, not tabs or newlines.

Using regular expressions

python

import re
s = input('Enter a string: ')
result = re.sub(r'\s+', '', s)
print(result)

This removes all kinds of whitespace including spaces, tabs, and newlines.

Complexity: O(n) time, O(n) space

Time Complexity

Splitting and joining the string each take linear time proportional to the string length.

Space Complexity

Extra space is used to store the list of words and the final joined string.

Which Approach is Fastest?

Using replace() is faster but only removes spaces. Using split() and join() or regex handles all whitespace but with slightly more overhead.

Approach	Time	Space	Best For
split() + join()	O(n)	O(n)	Removing all whitespace types
replace(' ', '')	O(n)	O(n)	Removing only spaces, faster
regex sub	O(n)	O(n)	Removing all whitespace with pattern flexibility