How To Insert A Python Variable Into A String?

As a Python developer, I got a requirement to insert variables into strings. There are several methods to achieve this, In this tutorial, I will explain how to insert a Python variable into a string using various methods with examples.

To insert a Python variable into a string using the f-string method, simply prefix your string with an f or F and place the variable inside curly braces {} within the string. For example, if you have a variable name = "John", you can use print(f"My name is {name}.") to include the variable in the output.

There are various methods to put a Python variable into a string. Let me explain each method with examples.

Table of Contents

1. Using the Comma Method

The comma method is easy to understand and use. It involves separating the string and the variable with a comma in the print function.

Syntax:

Here is the syntax:

print("string", variable)

Example:

Let me show you an example. Below is the Python code.

name = "John"
age = 28
print("My name is", name, "and I am", age, "years old.")

Output:

My name is John and I am 28 years old.

Here is the output you can see in the screenshot below:

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2. Using the Modulus Operator (%)

The modulus operator is an older method but is still widely used. It allows you to insert variables into a string by using % followed by a tuple of variables in Python.

Syntax:

Here is the syntax:

"string %s" % variable

Example:

Let me show you an example.

city = "New York"
temperature = 75
print("The temperature in %s is %d degrees Fahrenheit." % (city, temperature))

Output:

The temperature in New York is 75 degrees Fahrenheit.

Here is the exact output in the screenshot below:

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3. Using the format() Method

The format() method in Python allows you to insert variables into strings using curly braces {} as placeholders.

Syntax:

Here is the syntax:

"string {}".format(variable)

Example:

Now, let me show you an example.

first_name = "Alice"
last_name = "Johnson"
print("Hello, my name is {} {}.".format(first_name, last_name))

Output:

Hello, my name is Alice Johnson.

Here is the output in the screenshot below:

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4. Using F-Strings (Formatted String Literals)

F-strings are the most recent and recommended method for inserting variables into strings in Python. They are concise and easy to read, introduced in Python 3.6.

Syntax:

Here is an example.

f"string {variable}"

Example:

Let me show you an example.

state = "California"
population = 39500000
print(f"The population of {state} is approximately {population} people.")

Output:

The population of California is approximately 39500000 people.

Here is the output in the screenshot below:

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5. Using String Concatenation

String concatenation involves using the + operator to combine strings and variables in Python. This method requires converting non-string variables to strings using the str() function.

Syntax:

Here is the syntax:

"string" + str(variable)

Example:

Here is an example.

event = "concert"
tickets = 150
print("We sold " + str(tickets) + " tickets for the " + event + ".")

Output:

We sold 150 tickets for the concert.

Here is the exact output in the screenshot below:

Conclusion

In this tutorial, I explained, how to insert variables into strings in Python programming using various methods—comma, modulus operator, format(), f-strings, and string concatenation etc. If you still have questions, feel free to comment below.