How to Find Length of String in Python Quickly

In Python, you can find the length of a string using the len() function. Just pass the string as an argument to len(), and it returns the number of characters in that string.

Syntax

The syntax to find the length of a string is simple:

• len(string): Calls the len() function with the string you want to measure.
• Returns an integer representing the number of characters in the string, including spaces and special characters.

python

len(string)

Example

This example shows how to use len() to find the length of different strings.

python

my_string = "Hello, world!"
length = len(my_string)
print(f"The length of '{my_string}' is {length}.")

empty_string = ""
print(f"The length of an empty string is {len(empty_string)}.")

Output

The length of 'Hello, world!' is 13.
The length of an empty string is 0.

Common Pitfalls

Some common mistakes when finding string length include:

• Trying to use len without parentheses, like len(string) vs len string. The function must be called with parentheses.
• Confusing string length with byte size. len() counts characters, not bytes.
• For multi-byte characters (like emojis), len() counts each character as one, which may differ from visual length.

python

wrong = len("hello")
# SyntaxError: missing parentheses in call to 'len'

right = len("hello")
print(right)  # Output: 5

Output

5

Quick Reference

Remember these tips when using len() with strings:

• Use parentheses: Always call len() with parentheses.
• Counts characters: Includes letters, spaces, punctuation, and special characters.
• Empty string: Returns 0.

Key Takeaways

Use the built-in len() function to get the length of a string in Python.

len() counts all characters including spaces and punctuation.

Always include parentheses when calling len(), like len(string).

An empty string has length 0.

For multi-byte characters, len() counts each character as one.