How to Remove All Whitespace from String in Python

To remove all whitespace from a string in Python, including spaces between words, you need methods that target all whitespace characters throughout the entire string, not just at the ends like strip(). The most common approaches include using replace(), combining split() with join(), or employing regular expressions with re.sub() to eliminate all whitespace characters including spaces, tabs, and newlines.

Contents

• Understanding the Problem with strip()
• Method 1: Using replace()
• Method 2: Using join() with split()
• Method 3: Using Regular Expressions
• Method 4: Using str.translate()
• Comparing the Methods
• Performance Considerations
• When to Use Each Method

Understanding the Problem with strip()

The strip() method in Python only removes whitespace from the beginning and end of a string, leaving any internal whitespace untouched. As you’ve discovered in your code:

sentence = ' hello  apple  '
sentence.strip()  # Returns 'hello  apple' - spaces between words remain

This is why strip() doesn’t solve your problem of removing all whitespace, including between words. For complete whitespace removal, you need different approaches that process the entire string.

Method 1: Using replace()

The replace() method can be used to replace all whitespace characters with empty strings. However, by default it only replaces space characters:

sentence = ' hello  apple  '
no_whitespace = sentence.replace(' ', '')  # Returns 'helloapple'

For comprehensive whitespace removal including tabs and newlines, you can chain multiple replace calls or use regular expressions. According to the Sentry documentation, you can use str.replace() to replace space characters with empty strings: my_string_no_spaces = my_string.replace(" ", "").

Method 2: Using join() with split()

This is a popular one-liner approach that splits the string into words (removing all whitespace) and then joins them back without any separators:

sentence = ' hello  apple  '
no_whitespace = ''.join(sentence.split())  # Returns 'helloapple'

As shown in the DigitalOcean tutorial, you can remove all duplicate whitespace and newline characters by using the join() method with the split() method. The split() method breaks up the string into a list using the default separator of any whitespace character, then join() combines the list back into a string.

Method 3: Using Regular Expressions

Regular expressions provide the most comprehensive solution for removing all types of whitespace characters:

import re

sentence = ' hello  apple  \t\n'
no_whitespace = re.sub(r'\s+', '', sentence)  # Returns 'helloapple'

According to Stack Overflow, you can use re.sub(r'\s+', '', string) to remove all whitespace characters including spaces, tabs, and newlines. The pattern r'\s+' matches one or more whitespace characters, which are then replaced with an empty string.

The Sentry documentation explains that Python’s Regular Expressions module can be used with re.sub and "\s" to match all whitespace characters including tabs, non-breaking spaces, hair-width spaces, and more.

Method 4: Using str.translate()

For a very efficient solution, you can use the translate() method with a translation table:

sentence = ' hello  apple  '
# Create translation table mapping whitespace to None
translator = str.maketrans('', '', ' \t\n\r')
no_whitespace = sentence.translate(translator)  # Returns 'helloapple'

As mentioned in the Scaler tutorial, you can use the maketrans() function to map and replace all whitespaces with an empty string into an object dictionary, which is then translated to the final output string using the translate() function.

Comparing the Methods

Here’s a comparison of the different approaches:

Performance Considerations

For performance-critical applications, the translate() method is generally the fastest, followed by replace(), join()+split(), and re.sub(). As noted in the Scaler tutorial, the translate() method provides excellent performance for bulk string operations.

The Medium article by TechClaw demonstrates practical examples using the join() method:

original_string = "Python is amazing"
no_whitespace = ''.join(original_string.split())
print(no_whitespace)  # Output: "Pythonisamazing"

When to Use Each Method

• Use replace() when you only need to remove space characters and want the simplest syntax
• Use join()+split() for a clean one-liner that handles all whitespace types
• Use re.sub() when you need to handle complex whitespace patterns or other regex operations
• Use translate() for maximum performance in bulk string processing

The GeeksforGeeks article mentions that removing spaces from a string is a common task in Python with multiple solutions available, depending on the specific requirements.

Conclusion

• The strip() method only removes leading and trailing whitespace, not internal spaces
• Four main approaches exist: replace(), join()+split(), re.sub(), and translate()
• Each method has different performance characteristics and use cases
• For comprehensive whitespace removal including tabs and newlines, re.sub(r'\s+', '', s) or ''.join(s.split()) are the most practical choices
• Choose translate() for maximum performance in bulk operations
• Consider your specific needs for simplicity vs. performance when selecting the appropriate method

Sources

1. Stack Overflow - Remove all whitespace in a string
2. DigitalOcean - Effective Ways to Remove Spaces from Strings in Python
3. GeeksforGeeks - Remove spaces from a string in Python
4. Sentry - Remove whitespace from a string in Python
5. TechClaw - Remove all Whitespace from a String in Python
6. Scaler - How to Remove Whitespace From String in Python
7. W3Docs - Remove all whitespace in a string