How to check for an empty string in Python

There are four ways you can check if a string is empty or not in Python:

1. Use an if statement
2. Use an if not statement
3. Compare the len() result to 0
4. Use the strip() method

This tutorial shows how you can use each solution in practice

1. Use an if statement

An empty string evaluates to the boolean value False internally, so you can use an if statement to check if a string is empty.

The if statement block below runs only when the string is not empty:

my_str = ""

if my_str:
    print("My string is not empty")
else:
    print("String is empty")

When the string is empty, then the else block gets executed.

This if/else statement also works when the string is None as follows:

my_str = None

if my_str:
    print("My string is not empty")
else:
    print("String is empty")  # ✅

This is the most straightforward way to check if a string is empty in Python

2. Use an if not statement

The if not statement can be used to check for an empty string in Python.

The main difference between if and if not is that the if not statement executes the if block when the string is indeed empty:

my_str = ""

if not my_str:
    print("String is empty")  # ✅
else:
    print("My string is not empty")

In this solution, the else statement is executed only when the string is not empty.

3. Compare the len() result to 0

You can also check if a string is empty by comparing the len() result to 0.

An empty string has a length of 0, so you can use the equality comparison == operator as follows:

my_str = ""

if len(my_str) == 0:
    print("String is empty")  # ✅
else:
    print("My string is not empty")

4. Use the strip() method

Keep in mind that Python considers a string as empty only when there’s no character between the quotations.

If you have a white space character in the string, then Python will think it’s not an empty string. In the example below, the my_str variable has three white spaces:

my_str = "   "

if my_str:
    print("My string is not empty")  # ✅
else:
    print("String is empty")

Python runs the if block because it considers the string as not empty.

You can call the str.strip() method to remove white spaces in your string as follows:

my_str = "   "

if my_str.strip():
    print("My string is not empty")  
else:
    print("String is empty")  # ✅

Because the strip() method removes any leading and trailing white spaces, the returned string will be empty.

Depending on what you want to achieve, sometimes you might need to consider a string filled with spaces as empty.

Now you’ve learned how to check for an empty string in Python. Good work! 👍