The list is one of the essential built-in data structures in Python. It can store the ordered items’ collection. Sometimes, Python users need to check the length of list Python. For that, there are specific ways that users can use for checking list length.
Below, I have explained all those methods with relevant examples. But before that, let me give you a quick overview of the Python list. In python language, a list is a collection that has multiple data types. The benefit of using the list in Python is that it gives the freedom to change and rearrange the data.
Using commas, the user can separate the elements of the list. Moreover, the square brackets use to enclose the list. Now, let’s check how to check the length of list Python.
How do you find the length of a list Python?
Below, I have explained two different ways to find out the length of the list in Python. Check both of them one by one.
- Len() method
One of the most simple methods for finding the length of list Python is the len() function. It is an in-built function that users can use easily.
This method is the easiest and quick way to know the length of a list in the program. Len() is considered to be the most traditional technique acquired by many programmers in today’s time.
Len() can work with the tuple, list, dictionary, string, etc., allowing one argument at a time. The number of elements in the list in the return value is always an integer.
Let us see an example that helps to understand Len() much easier.
(‘Number of items in the list = ‘, 8)
Another example of len() function is:
(‘Number of items in tuple are = ‘, 6)
|Is the len() function method limited to the list only?|
No, not at all!!
The len() method does not limit to the list, but its arguments can be any type like list, tuple, string, range, and more. Moreover, Python users can use the collection of these objects as the parameter.
Therefore, we can say that you can use the len() method for checking the length of the total number of items in the dictionary, set or frozen set, etc.
- Naive Method
Another most basic and yet easy to deal with method is the Naive method. However, the len() method is considered to be on the top. The Naive method is also considered a popular method in the Length of list Python.
Talking about the Naive method, it forms a circular loop and expands the counter. It will keep on expanding unless the final element becomes its count.
There are many other efficient techniques in the field of the list in Python. But the most simple and the best strategy used for the list is the naive method.
Let us see an example that helps to understand the Naive method much easier.
The list is : [2, 4, 6, 8, 10, 12]
Length of the list in Python is : 6
Take a look at another example of the naive method:
The list is : [‘Course’, ‘Mentor’, 1, 2, 3]
Length of the list in Python is : 5
How long can a Python list be?
As per the source code, the list can have the size of PY_SSIZE_T_MAX/sizeof(PyObject*). On the other hand, in the regular 32-bit system, the list size could be (4294967295 / 2) / 4 or 536,870,912.
Finally, we can say that the Python list can have a maximum size of 536,870,912 elements on the 32-bit system.
Which method should I prefer: Naive or len()?
Well, it has been seen that the len() function in Python is preferred more for determining the length of list Python. There are two main reasons for this:
- Simplicity: If we talk about code simplicity, then len() provides more simple code than the loop method used in naive. Besides this, it also offers higher readability than that of the naive method.
- Work more quickly: The len() takes O(1) to work in complexity. On the other hand, if you use len() with a loop, it takes hardly O(n) to get executed. The len() function requires constant time, and it works without depending on the list size. It is possible just because the objects such as the list track their own length. When you use the len() function, it just “looks up” the object length attributes to return the value.
Finding the length of the list in Python is not that complex. It can be easily solved by using the most popular method. This blog helped you know how to check the length of list Python using two different methods.
The first one is the len() function method, which is very popular in use. The second most popular method is the Naive method. These were the best two methods for finding the length of the list in Python.
I have mentioned some great examples that can even make it easy for you to understand. So, I hope the concept of finding the length of the list in Python has been cleared to you.
If you still have any queries, comment in the below comment section. To check different Python projects for beginners – Click Here.
Frequently Asked Questions
What does Len() do in Python?
The Python len() function is used for returning the item number in the iterable objects. The iterable objects can be like strings and lists. It means that the object value will be assigned to the particular index value. This value always refers to the particular and individual object value.
What are lists in Python?
The list considers as the mutable and ordered Python container. It is the most common data type or structure in Python. The square brackets are used for creating a list and putting the elements in it. Remember, lists can have different types of elements and also duplicated elements.