// Tutorial //

Python Concatenate String and Int

Published on August 3, 2022 · Updated on September 20, 2022
Default avatar
By Pankaj
Developer and author at DigitalOcean.
Python Concatenate String and Int

Introduction

Python supports string concatenation using the + operator. In most other programming languages, if we concatenate a string with an integer (or any other primitive data types), the language takes care of converting them to a string and then concatenates it.

However, in Python, if you try to concatenate a string with an integer using the + operator, you will get a runtime error.

Example

Let’s look at an example for concatenating a string (str) and an integer (int) using the + operator.

string_concat_int.py
current_year_message = 'Year is '

current_year = 2018

print(current_year_message + current_year)

The desired output is the string: Year is 2018. However, when we run this code we get the following runtime error:

Traceback (most recent call last):
  File "/Users/sammy/Documents/github/journaldev/Python-3/basic_examples/strings/string_concat_int.py", line 5, in <module>
    print(current_year_message + current_year)
TypeError: can only concatenate str (not "int") to str

So how do you concatenate str and int in Python? There are various other ways to perform this operation.

Using the str() Function

We can pass an int to the str() function it will be converted to a str:

print(current_year_message + str(current_year))

The current_year integer is returned as a string: Year is 2018.

Using the % Interpolation Operator

We can pass values to a conversion specification with printf-style String Formatting:

print("%s%s" % (current_year_message, current_year))

The current_year integer is interpolated to a string: Year is 2018.

Using the str.format() function

We can also use the str.format() function for concatenation of string and integer.

print("{}{}".format(current_year_message, current_year))

The current_year integer is type coerced to a string: Year is 2018.

Using f-strings

If you are using Python 3.6 or higher versions, you can use f-strings, too.

print(f'{current_year_message}{current_year}')

The current_year integer is interpolated to a string: Year is 2018.

Conclusion

You can check out the complete Python script and more Python examples from our GitHub repository.


Want to learn more? Join the DigitalOcean Community!

Join our DigitalOcean community of over a million developers for free! Get help and share knowledge in our Questions & Answers section, find tutorials and tools that will help you grow as a developer and scale your project or business, and subscribe to topics of interest.

Sign up
About the authors
Default avatar
Pankaj

author

Developer and author at DigitalOcean.

Still looking for an answer?

Was this helpful?

num = ([3,4,3,2,1]) print(reduce(lambda x,y: x * 10 + y ,num)) 34321

- Egmon

    it works fine but takes too much time for instance if we have to convert integer to string 200 times , you would be able to notice the time taken to execute the code. How can we deal with that to make our code more efficient?

    - future googler

      Write a python program that asks the user how many coins of various types they have, and then prints the total amount of money in rupees.

      - M P ANUPAMA

        Hey Pankaj, thanks for sharing this article. This helped me to have a better understanding of formats used with print function

        - Anupinder singh