Python – Check If String Contains Only Letters and Numbers

In this tutorial, we will look at how to check if a string contains only letters and numbers in Python with the help of examples.

check if string in python contains only letters and numbers

You can use the string isalnum() function to check if a string contains only letters (that is, alphabets) and/or numbers in Python. The following is the syntax –

# check if string s contains only alphanumeric characters
s.isalnum()

It returns True if all the characters in the string are alphanumeric (containing only alphabets and/or numbers). If any of the characters is not alphanumeric, it returns False.

Let’s look at an example.

# create a string
s = "Bunny123"
# check if string contains only alphanumeric characters
print(s.isalnum())

Output:

True

We get True as the output. This is because all the characters in the string s above are either letters or numbers.

Let’s look at another example.

# create a string
s = "Bunny_123"
# check if string contains only alphanumeric characters
print(s.isalnum())

Output:

False

Here, we get False as the output. This is because not all characters in the string s above are alphanumeric. One of the characters in the string, “_” is neither an alphabet nor a digit.

For more on the string isalnum() function, refer to its documentation.

You might also be interested in –


Subscribe to our newsletter for more informative guides and tutorials.
We do not spam and you can opt out any time.


Leave a Reply

Your email address will not be published.