Python is one of the most popular and easy to learn programming languages around at the moment. While the syntax may be relatively easier to understand, the language is still quite powerful and has most if not all the tools a relatively higher-level programming language might.
Today we’re talking about lists in Python and how you can find the length of a list.
What is a Python list?
A list in Python or any other programming language is a data type used to store a sequence of various other data types. It’s exactly what it sounds like — it’s a list.
There are other methods to store sequences; in fact, there are six, but lists are one of the most popular ones. It’s defined as a collection of values or items of different types separated by commas and enclosed within square brackets.
Here’s the syntax used to define Python lists.
listname = ['item1', 2, 'item3']
Also read: Python vs Java vs C/C++: Key differences and Pros-Cons
How to find a Python list length?
There are two methods you can use to find a list’s length.
- Using the len() function.
- Using a loop.
We’ll be going over both methods.
Finding Python list length using the len() function
The len() function is a built-in method for finding the total number of items in sequenced data types such as lists, tuples, arrays, and dictionaries. All the function needs is an argument providing the list in question.
Here’s the basic syntax used with the function.
len(list_name)
Here’s an example.
ListName = ["Hello", "World"]
print ("Length of the list = ", len(ListName))
The output for the above snippet will be 2, as there are two items in the list.
Finding Python list length using a loop
Alternatively, you can use a loop to go over each list item and operate on them.
Here’s an example.
list= ['This', 'is', 'a', 'list']
counter = 0
for capital in capitals:
counter = counter + 1
print("The list has {0} elements.".format(counter))
We recommend using the len() method every time you need only to find the length of a list as the function is a lot less complicated to write and is purpose-built for that functionality. If you need to operate on a list’s items, however, you will have to use the looping method.
Also read: Top 7 Python IDEs and Text Editors for Data Science Applications