How to Find the Length of a List in Python

Lists are one of the most commonly used data types in Python and are used to store collections of items of the same type.

This article shows how to find the length of a list.

len() Function #

Python has a built-in function len() that returns the length of a given object. The object can be a list
, tuple, string, dictionary, etc.

The syntax of the len() function is as follows:

The function accepts only one argument. The returned value is an integer that is the number of elements in the list.

Here is an example:

capitals = ['Tokyo', 'Sofia', 'London', 'Budapest']

list_len = len(capitals)

print("The list has {0} elements.".format(list_len))

The list has 4 elements.

Using Loop #

Another way to get the length of a list is to use the for
loop. This works by setting up a counter and looping through all the elements of the list. On each iteration, the current value of the counter variable is incremented by one.

Below is a sample code that shows how to find the number of elements in a given list using the for loop:

capitals = ['Tokyo', 'Sofia', 'London', 'Budapest']
counter = 0

for capital in capitals:
  counter = counter + 1

print("The list has {0} elements.".format(counter))

The list has 4 elements.

This method is not very Pythonic. You should always prefer using the len() function.

Conclusion #

To find the length of a list in Python list, use the len() function.

If you have any questions or feedback, feel free to leave a comment.