Python - Remove N characters after K

Python – Remove N characters after K

Last Updated : 30 Aug, 2020

Given a String, remove N characters after K character.

Input : test_str = ‘ge@987eksfor@123geeks is best@212 for cs’, N = 3, K = ‘@’
Output : ‘geeksforgeeks is best for cs’
Explanation : All 3 required occurrences removed.

Input : test_str = ‘geeksfor@123geeks is best for cs’, N = 3, K = ‘@’
Output : ‘geeksforgeeks is best for cs’
Explanation : @123 is removed.

Method #1 : Using re.sub()

In this, we specify appropriate regex to capture the element and to remove next N occurrences from String. The sub() is used to perform replacement.

Python3

# Python3 code to demonstrate working of  
# Remove N characters after K 
# Using re.sub() 
import re 
  
# initializing strings 
test_str = 'geeksfor@123geeks is best@212 for cs'
  
# printing original string 
print("The original string is : " + str(test_str)) 
  
# initializing N  
N = 3
  
# initializing K  
K = '@'
  
# using re.sub() to perform task  
res = re.sub(r'\@...', '', test_str) 
  
# printing result  
print("The String after removal : " + str(res))  

Output

The original string is : geeksfor@123geeks is best@212 for cs
The String after removal : geeksforgeeks is best for cs

Method #2 : Using re.sub() + occurrence option

This is similar to above, just using 4th argument of re.sub() to control the occurrence counts we wish to perform replace.

Python3

# Python3 code to demonstrate working of  
# Remove N characters after K 
# Using re.sub() + occurrence option 
import re 
  
# initializing strings 
test_str = 'geeksfor@123geeks is best@212 for cs'
  
# printing original string 
print("The original string is : " + str(test_str)) 
  
# initializing N  
N = 3
  
# initializing K  
K = '@'
  
# using re.sub() to perform task  
# controlling occurrence using 4th arg. 
# removes just 1st occurrence 
res = re.sub(r'\@...', '', test_str, 1) 
  
# printing result  
print("The String after removal : " + str(res))  

Output

The original string is : geeksfor@123geeks is best@212 for cs
The String after removal : geeksforgeeks is best@212 for cs

Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics.

To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course.

My Personal Notes

Related Articles

Python3

Python3