Remove all the underscores from a string in Python

To remove all underscores (_) from a string in Python, you can use several methods. Each method has its advantages depending on the use case.

          Remove underscores from string in Python

1. Using str.replace()

The replace() method replaces all occurrences of a specific substring in a string with another substring. To remove underscores, replace _ with an empty string (“”).

original_string = "hello_world_this_is_python"
cleaned_string = original_string.replace("_", "")
print(cleaned_string) 

Output:

helloworldthisispython

Explanation:

1. original_string:
   • This is the string containing underscores (“_”) that we want to remove.
   • Example: "hello_world_this_is_python".
2. replace() Method:
   • The str.replace(old, new) method replaces all occurrences of old (in this case, _) with new (an empty string, "").
   • This effectively removes all underscores from the string.
3. cleaned_string:
   • This holds the new string after the underscores have been removed.
4. print(cleaned_string):
   • Outputs the cleaned string without underscores.

• Advantage: Simple and direct.
• Use case: Works best for straightforward replacements.

2. Using Regular Expressions (re.sub)

The re.sub() function from the re module allows more advanced pattern matching and replacement. To remove underscores, you can match them using _ as the pattern.

import re

original_string = "hello_world_this_is_python"
cleaned_string = re.sub("_", "", original_string)
print(cleaned_string) 

Output:

 helloworldthisispython

Explanation:

1. Import the re module:
   • The re module in Python provides support for regular expressions.
2. original_string:
   • This is the input string containing underscores (_).
   • Example: "hello_world_this_is_python"
3. re.sub(pattern, replacement, string):
   • This function replaces all occurrences of a pattern with a specified replacement in the given string.
   • pattern:
     • The underscore ("_") is used as the pattern to be matched.
   • replacement:
     • An empty string ("") is provided, which removes all matched patterns (underscores).
   • string:
     • The string to process (original_string).
4. cleaned_string:
   • This is the string after the removal of all underscores.
5. Output the result:
   • The print() statement displays the string without underscores.

• Advantage: Supports complex patterns if you want to match multiple characters.
• Use case: Ideal for strings requiring advanced manipulation.

3. Using a List Comprehension

Iterate over each character and keep only those that are not underscores.

original_string = "hello_world_this_is_python"
cleaned_string = "".join([char for char in original_string if char != "_"])
print(cleaned_string)  

 helloworldthisispython