Python

Python List Length

Python List is a changeable and ordered sequence, as we all know about this fact. It may contain both heterogeneous and homogeneous elements. In Python, it is a widely used data structure. We occasionally need to know the length of a list to traverse it or perform other operations on it. Len() is a built-in function that returns the total number of elements in a list, sequence, arrays, dictionary, or other data structure. The length of a given list is returned by the len() method, which accepts a list as an input. In Python, the len() function is one of the most popular methods for determining the size of a provided list.

This part will look at the various methods for determining the length of a list in Python. The length of the list refers to determining the size of the list’s size or the number of items.

Note: All three examples demonstrated in this guide will use the “temp.py” file that is created in the Spyder IDE tool. The operating system used for the implementation of these three examples is “Windows 10”. The choice of operating system and compiler are all dependent on user convenience.

Example 1

A list of some items is formed in this demonstration. The items are made up of a mix of numbers and characters from a string. After that, the len() function is used. The print function is used to showcase the returned value, which is allocated to a variable. This example’s code can be found here.

    X = ["Hi", "readers",0, 1, 2, 3]

    print ("Number of items in the list = ", len(X))

Compile the above-stated code in Spyder IDE by using the “Run” button or pressing the “F5” key from your system’s keyboard. Once done, a black console screen will pop out, displaying the length of the declared list. In our case, the length is “6”.

Example 2: for loop

A list of strings is formed in this scenario. We have a list that has the names of four persons. The size of each string element in the list is then determined using a for a loop. The print statement will show the length of every name mentioned in the above list, and after that, the length of the whole list will be displayed.

    Names = ['Kalsoom', 'Alex', 'Leena', 'hem']

    for x in Names:

    print(x, "=", len(x))

    print ("***@@@@***")

    print ("Length of the list  = ", len(Names))

Compile the above-stated code in Spyder IDE by using the “Run” button or pressing the “F5” key from your system’s keyboard. Once done, a black console screen will pop out, displaying the length of the declared list. In our case, the length is “4”. The main difference in the output can be determined here that this code will display the size of individual elements of the list using a for a loop.

Example 3: array length

The following illustration demonstrates how to find an array’s length. After adding the array module, the first step is to construct an array. The array length is then obtained utilizing the len() method, which is shown using the print function:

    from array import array

    array_length=array('b',[1, 2, 3, 4, 5, 6, 7, 8, 9, 10])

    print("The array length is:", len(array_length))

Compile the above-stated code in Spyder IDE by using the “Run” button or pressing the “F5” key from your system’s keyboard. Once done, a black console screen will pop out, displaying the length of the declared array. In our case, the length is “10”. Check that only the array length has been shown instead of the whole list.

Conclusion

We summarize in this tutorial that obtaining the length of a list in Python is fairly simple and that there are several methods for determining the length or size of a provided list. In this article, we learned that the most popular and straightforward technique is to use the len() method, a Python built-in function for determining the length of a list. The “for” loop or the naive technique are the other two options. Out of all of the ways listed above, programmers consider Python’s built-in len() method to be the ideal approach for determining the size of a list.

About the author

Kalsoom Bibi

Hello, I am a freelance writer and usually write for Linux and other technology related content