In this Python article, I will explain how to remove character from string Python by index in different ways using different methods present in Python. In the process of understanding all the methods, we will see some illustrative examples related to the methods.
Python strings are sequences of characters and can be indexed to retrieve specific characters. Often, while programming, we might need to remove a character from a string based on its index. Since Python strings are immutable, we can’t directly modify them. Instead, we need to create a new Python string that doesn’t have the character at the given index.
Methods to remove character from string Python by index
There are many different methods to remove character from string Python by index.
- string slicing with concatenation
- Native method
- replace() method
- split() method
- list comprehension
Let’s see them one by one using some illustrative examples:
Method 1: Python remove character from string by index using string slicing with concatenation
To extract a slice of the elements from the collection of elements, use the slice() method in Python. By specifying their indices, users can access a specific range of elements. Using a Python string slice, one can trim the string before position i and after position i.
Moreover, we can join two or more strings in Python. String concatenation is the process of using operators or functions to combine two or more Python strings. By using the + operator we are going to concatenate two strings in Python.
Example 1: Let’s take an example and check how to remove character from string python by index using the slice and concatenation method.
state_name_in_USA = 'Alaska, Arizona, Alabama' print("Input string: ",state_name_in_USA ) result = state_name_in_USA[:1] + state_name_in_USA[2:] print ("Removing character from second index in string : ", result)
Input string: Alaska, Arizona, Alabama Removing character from second index in string : Aaska, Arizona, Alabama
This is how we can remove character from string Python by index using the slice and concatenation method.
Example 2: Imagine we are processing city names, and we realize that the city “New Yorkk” has an extra ‘k’. We need to remove the 2nd last character from the Python string.
def remove_char_at_index(s, index): return s[:index] + s[index+1:] city = "New Yorkk" corrected_city = remove_char_at_index(city, -2) print(corrected_city)
Note: In this case, we are removing the 2nd last ‘k’ not the last ‘k’.
Method 2: Remove character in string Python by index using Native method
In this, we will use the concept of using a for loop to remove a character from a string by its index can be accomplished by iterating over the Python string and collecting characters that aren’t at the target index to create a new string in Python from the initial for instances when the index is i.
Bikes_in_USA = "Harley-Davidson, BMW" print("Original string :", Bikes_in_USA) result = "" for m in range(len(Bikes_in_USA)): if m != 3: result = result + Bikes_in_USA[m] print("Remove character from input string by index 3 : ", result)
Output: We have created an input string named ‘Bikes_in_USA’ and then created an empty Python string in which the new result will be stored. Next, we used the for loop and iterated the values.
Original string : Harley-Davidson, BMW Remove character from input string by index 3 : Harey-Davidson, BMW
Example 2: Imagine we’re cataloging books and notice a typo in the title “The Great Gatsbby“. Let’s correct it using a for loop in Python.
def remove_char_at_index(s, index): new_string = "" for i in range(len(s)): if i != index: new_string += s[i] return new_string book_title = "The Great Gatsbby" corrected_title = remove_char_at_index(book_title, 15) print(corrected_title)
Output: The function with the for loop removes the extra ‘b’ at the 15th index, providing the correct title.
The Great Gatsby
Method 3: Remove ith character from string Python using
The str.replace() method is designed to replace occurrences of a substring. To use it for our purpose:
- Identify the character at the given index.
- Replace the first occurrence of that character with an empty string.
When replacing a single character with a new character in Python, use the replace() method, and with this method, we will replace the character at the i index for the empty substring provided as (“).
Syntax: Let’s have a look at the syntax and understand the working of the str.replace() method in Python.
str.replace(old, new, count)
|old||This parameter defines the string that will be replaced.|
|new||Replace the existing value with a new one (a character or a string).|
|count||An integer value that indicates how many instances of the old character or substring we want to replace with the new one. It is an optional parameter.|
Example 1: If we want to remove the character from the string then we have to mention the index number.
def del_character(t, m): for l in range(len(t)): if l==m: t=t.replace(t[m],"",1) return t Country_name = "U.S.A, China" # Remove 3rd index character m = 3 print(del_character(Country_name,m-1))
Output: In the above code first, we define a function that takes a string and an index I then remove the character at that index. Next, we execute a for loop from 0 to the length of the input Python string and check if the present iteration is equal to the index i. If identified, replace an empty string in Python for the character at index i.
Example 2: On a website showcasing famous American monuments, we need to find the entry “Statuee of Liberty“. We need to correct this by removing the extra ‘e’ using Python.
def remove_char_at_index(s, index): return s.replace(s[index], '', 1) monument = "Statuee of Liberty" corrected_monument = remove_char_at_index(monument, 6) print(corrected_monument)
Output: The function with the replace() method, removes the seventh character (‘e‘) from “Statuee of Liberty“.
Statue of Liberty
This is how we can use the replace() function in Python to remove character from string Python by index.
Method 4: Remove character from string Python at index using split() method
The split() method can divide a string in Python into parts. We can leverage this by splitting our string at the desired index and then joining it back.
The Python string will be divided into two halves in this method, one before index i and the other after index i. The string that will not contain the ith character can then be generated by combining these two strings.
Scenario: Consider that we’re reading a review of American fast-food chains and come across the word “McDonald’ss“. The extra ‘s’ needs to be removed.
def remove_char_at_index(s, index): return s[:index] + ''.join(s[index:].split(s[index], 1)[1:]) chain = "McDonald'ss" corrected_chain = remove_char_at_index(chain, -1) print(corrected_chain)
This way we can simply use the split() with join() function to remove character from string Python by index.
Method 5: Python string remove character at index using List comprehension
List comprehensions provide a concise way to manipulate lists in Python. We can enumerate over the string, skip the character at the given index, and then join it back into a Python string.
Scenario: During a US presidential election, a candidate’s name “Joeh Biden” is misspelled with an extra ‘h’. We need to correct it using Python methods.
def remove_char_at_index(s, index): return ''.join([char for idx, char in enumerate(s) if idx != index]) candidate = "Joeh Biden" corrected_candidate = remove_char_at_index(candidate, 3) print(corrected_candidate)
Output: The function removed the fourth character (‘h’) from “Joeh Biden”.
This way we can use list comprehension with the join() function to remove character from string Python by index.
String manipulation is a common task in Python programming, and there are multiple ways to remove character from string Python by index like string slicing, for loop, replace() method, split() function, and list comprehension. The method one chooses largely depends on the specific requirements of the project and their personal preferences.
You may also like to read:
- Remove the last character from a string in Python
- How to Python Append List to Another List
- How to convert a set to a list in Python
I am Bijay Kumar, a Microsoft MVP in SharePoint. Apart from SharePoint, I started working on Python, Machine learning, and artificial intelligence for the last 5 years. During this time I got expertise in various Python libraries also like Tkinter, Pandas, NumPy, Turtle, Django, Matplotlib, Tensorflow, Scipy, Scikit-Learn, etc… for various clients in the United States, Canada, the United Kingdom, Australia, New Zealand, etc. Check out my profile.