How To Convert a String to a Float in Python

Updated on September 21, 2022


How To Convert a String to a Float in Python


In this article, we will use Python’s float() function to convert strings to floats. And we will also use Python’s str() function to convert floats to strings.

It is important to properly convert the data types before using them for calculations and concatenations in order to prevent runtime errors.


In order to complete this tutorial, you will need:

This tutorial was tested with Python 3.9.6.

Using the float() function

We can convert a string to float in Python using the float() function. This is a built-in function used to convert an object to a floating point number. Internally, the float() function calls specified object __float__() function.


Let’s look at an example of converting a string to float in Python:

input_1 = '10.5674'

input_1 = float(input_1)

print('Float Value =', input_1)


<class 'float'>
Float Value = 10.5674

The string value of '10.5674' has been converted to a float value of 10.5674.

Why do we need to convert a string to float?

If we are receiving float value from user input through the terminal or reading it from a file, then they are string objects. We have to explicitly convert them to float so that we can perform necessary operations on them, such as addition, multiplication, etc.

input_1 = input('Please enter first floating point value:\n')
input_1 = float(input_1)

input_2 = input('Please enter second floating point value:\n')
input_2 = float(input_2)

print(f'Sum of {input_1} and {input_2} is {input_1+input_2}')

Note: If you are not familiar with string formatting using f prefix, please read f-strings in Python.

Let’s run this code and provide float values for input_1 and input_2:

Please enter first floating point value:
Please enter second floating point value:
Sum of 10.234 and 2.456 is 12.69

The resulting sum of 10.234 and 2.456 is 12.69.

Ideally, we should use a try-except block to catch exceptions in case of invalid input from the user.

Using the str() function

We can also convert a float to a string using the str() function. This might be required in situations where we want to concatenate float values.


Let’s look at an example:

input_1 = 10.23
input_2 = 20.34
input_3 = 30.45

# using f-string from Python 3.6+, change to format() for older versions
print(f'Concatenation of {input_1} and {input_2} is {str(input_1) + str(input_2)}')
print(f'CSV from {input_1}, {input_2} and {input_3}:\n{str(input_1)},{str(input_2)},{str(input_3)}')
print(f'CSV from {input_1}, {input_2} and {input_3}:\n{", ".join([str(input_1),str(input_2),str(input_3)])}')

Let’s run this code:

Concatenation of 10.23 and 20.34 is 10.2320.34
CSV from 10.23, 20.34 and 30.45:
CSV from 10.23, 20.34 and 30.45:
10.23, 20.34, 30.45

Concatenating 10.23 and 20.34 produces the string '10.2320.34'. This code also produces two versions of comma-separated values (CSV).

If we don’t convert float to string in the above program, the join() function will throw an exception. Also, we won’t be able to use the + operator to concatenate as it will add the floating point numbers.


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


Thanks for learning with the DigitalOcean Community. Check out our offerings for compute, storage, networking, and managed databases.

Learn more about us

About the authors
Default avatar


Still looking for an answer?

Ask a questionSearch for more help

Was this helpful?

Try DigitalOcean for free

Click below to sign up and get $200 of credit to try our products over 60 days!

Sign up

Join the Tech Talk
Success! Thank you! Please check your email for further details.

Please complete your information!

Featured on Community

Get our biweekly newsletter

Sign up for Infrastructure as a Newsletter.

Hollie's Hub for Good

Working on improving health and education, reducing inequality, and spurring economic growth? We'd like to help.

Become a contributor

Get paid to write technical tutorials and select a tech-focused charity to receive a matching donation.

Welcome to the developer cloud

DigitalOcean makes it simple to launch in the cloud and scale up as you grow — whether you're running one virtual machine or ten thousand.

Learn more
DigitalOcean Cloud Control Panel