Add a character to a specific position in a string using Python

In this article, we will learn how to add a character to a specific position in a string in Python. Python strings are immutable, so these methods create new strings rather than modifying the original.

Methods to Add Characters to Strings

The following are the various methods to accomplish this task ?

• Using the '+' operator

• Using join() function

• Using format() function

Method 1: Using the '+' Operator

The '+' operator concatenates strings by combining them at specified positions. This is the most straightforward method for adding characters.

Adding Character at the End

The following program adds a character at the end of a string using the '+' operator ?

# input string
input_string = "tutorialspoin"

# adding a character at the end using the + operator
result = input_string + 't' 

# printing the resultant string
print("Adding 't' at the end:", result)

Adding 't' at the end: tutorialspoint

Adding Character at a Specific Position

Use string slicing to insert a character at any position within the string ?

# input string
input_string = "tutorialsoint"

# adding character 'p' at index 9 using slicing
result = input_string[:9] + 'p' + input_string[9:]

# printing the resultant string 
print("Adding 'p' at index 9:", result)

Adding 'p' at index 9: tutorialspoint

Adding Character at the Beginning

The following program adds a character at the start of a string ?

# input string
input_string = "utorialspoint"

# adding character 't' at the beginning
result = 't' + input_string

# printing the resultant string 
print("Adding 't' at the beginning:", result)

Adding 't' at the beginning: tutorialspoint

Method 2: Using the join() Function

The join() function concatenates sequence elements with a specified separator. It's efficient for combining multiple parts of a string.

Example

The following program demonstrates adding characters at different positions using join() ?

# Adding at the end
input_string_1 = "tutorialspoin"
result_1 = ''.join([input_string_1, 't']) 
print("Adding 't' at the end:", result_1)

# Adding at specific position (index 9)
input_string_2 = "tutorialsoint"
result_2 = ''.join([input_string_2[:9], 'p', input_string_2[9:]]) 
print("Adding 'p' at index 9:", result_2)

# Adding at the beginning
input_string_3 = "utorialspoint"
result_3 = ''.join(['t', input_string_3]) 
print("Adding 't' at the beginning:", result_3)

Adding 't' at the end: tutorialspoint
Adding 'p' at index 9: tutorialspoint
Adding 't' at the beginning: tutorialspoint

Method 3: Using the format() Function

Python's format() function allows inserting values into placeholders within strings. This method is useful for template-based string construction.

Adding Character at Different Positions

The following program demonstrates using format() to add characters ?

# Adding at the end
result_1 = "tutorialspoin{}".format('t')
print("Adding 't' at the end:", result_1)

# Adding at specific position
result_2 = "tutorials{}oint".format('p')
print("Adding 'p' at index 9:", result_2)

# Adding at the beginning
result_3 = "{}utorialspoint".format('t') 
print("Adding 't' at the beginning:", result_3)

Adding 't' at the end: tutorialspoint
Adding 'p' at index 9: tutorialspoint
Adding 't' at the beginning: tutorialspoint

Comparison of Methods

Conclusion

The '+' operator is most intuitive for simple character insertion, while join() is efficient for multiple concatenations. Use format() when you need template-based string construction with placeholders.