How to append a string in Python?

In this tutorial, we will see different ways to append a string in Python. The most efficient methods are using the += operator, join() function, and f-strings.

We know that strings are immutable in Python, which means we cannot change the string variable’s value once it’s declared and assigned. However, we can always return a new string.

Append to a String in Python

We will take a look at 3 different ways to append a string in Python.

1. Using += operator
2. Using string.join() method
3. Using Python f-strings

Method 1: Using += operator to append a string

The +=(plus equal) operator is similar to any other language that concatenates two strings and returns a new string in Python without changing the original string.

Example: Append to a string using += operator

# Python program to append to a string using += operator

first_name="Bing"
last_name=" Chandler"

# printing first name
print("The first name is: " + str(first_name))

# printing last name
print("The last name is: " + str(last_name))

# Using += operator adding one string to another
first_name += last_name

# print concatenated string
print("The concatenated string is: " + first_name)

Output

The first name is: Bing
The last name is:  Chandler
The concatenated string is: Bing Chandler

Method 2: Using join() function to append a string

Another way to append strings in Python is using the join() method. It has an advantage over the += operator as it can append multiple strings or a list of strings. 

Example: Append to a string using the join() function

In this example, we pass a list of strings to the join() function, which concatenates them together and returns to the output string.

# Python program to append a string using join() function

first_name="Bing"
last_name=" Chandler"

# printing first name
print("The first name is: " + str(first_name))

# printing last name
print("The last name is: " + str(last_name))

# Using join() method to append a string
result= "".join([first_name,last_name])

# print concatenated string
print("The concatenated string is: " + result)

Output

The first name is: Bing
The last name is:  Chandler
The concatenated string is: Bing Chandler

Method 3: Using f-strings to append a string

If you use Python 3.6 and above version, you can leverage f-strings in Python to append a string.

F-strings provide a way to embed expressions inside string literals, using a minimal syntax. F-strings are prefixed with “f” which contains expression inside braces. These expressions are replaced with their values.

Example: Append to a string using the f-string

# Python program to append a string using f-string

first_name="Bing"
last_name=" Chandler"

# printing first name
print("The first name is: " + str(first_name))

# printing last name
print("The last name is: " + str(last_name))

# Using f-string to append a string
result= f"{first_name}{last_name}"

# print concatenated string
print("The concatenated string is: " + result)

Output

The first name is: Bing
The last name is:  Chandler
The concatenated string is: Bing Chandler