What is the name of the function that returns the number of values in a list?
Python List count()In this tutorial, we will learn about the Python List count() method with the help of examples. Show The count() method returns the number of times the specified element appears in the list. Example# create a list numbers = [2, 3, 5, 2, 11, 2, 7]# check the count of 2
count = numbers.count(2)
print('Count of 2:', count)
# Output: Count of 2: 3sort() methodThe sort() method is a built-in Python method that, by default, sorts the list in ascending order. However, you can modify the order from ascending to descending by specifying the sorting criteria. ExampleLet's say you want to sort the element in prices in ascending order. You would type prices followed by a . (period) followed by the method name, i.e., sort including the parentheses. prices = [238.11, 237.81, 238.91] prices.sort() print(prices) [237.81, 238.11, 238.91]type() functionFor the type() function, it returns the class type of an object. ExampleHere we will see what type of both fam and fam2 are: fam = ["liz", 1.73, "emma", 1.68, "mom", 1.71, "dad", 1.89] fam ['liz', 1.73, 'emma', 1.68, 'mom', 1.71, 'dad', 1.89]Let's see what the type of the object is: type(fam) listNow, let's look at fam2. fam2 = [["liz", 1.73], ["emma", 1.68], ["mom", 1.71], ["dad", 1.89]] fam2 [['liz', 1.73], ['emma', 1.68], ['mom', 1.71], ['dad', 1.89]]Let's see what the type of the object is: type(fam2) listThese calls show that both fam and fam2 are in fact lists. append() methodThe append() method will add certain content you enter to the end of the elements you select. ExampleIn this example, let’s extend the string by adding “April” to the list with the method append(). Using append() will increase the length of the list by 1. months = ['January', 'February', 'March'] months.append('April') print(months)When you run the above code, it produces the following result: ['January', 'February', 'March', 'April']Python List count() methodPython List count() is an inbuilt function in Python that returns the count of how many times a given object occurs in a List. The count() function is used to count elements on a list as well as a string.
Example 1: Use of count()Python3
Output: 4 3 2Example 2: TypeErrorPython3
Output: Traceback (most recent call last): File "/home/41d2d7646b4b549b399b0dfe29e38c53.py", line 7, in print(list1.count(1, 2)) TypeError: count() takes exactly one argument (2 given)Example 3: Count Tuple and List Elements Inside ListPython3
Output: 2 2Practical ApplicationLet’s say we want to count each element in a list and store it in another list or say dictionary. Python3
Output: [['Mat', 1], ['Cat', 3], ['Sat', 2], ['Bat', 1]] {'Bat': 1, 'Cat': 3, 'Sat': 2, 'Mat': 1}Attention geek! Strengthen your foundations with the Python Programming Foundation Course and learn the basics. To begin with, your interview preparations Enhance your Data Structures concepts with the Python DS Course. And to begin with your Machine Learning Journey, join the Machine Learning - Basic Level Course
Article Tags :
Python
Python-Built-in-functions python-list python-list-functions Practice Tags :
python-list
Read Full Article
What do you want to do?
List in PythonA list in Python is implemented to store the sequence of various types of data. However, there are six data types in Python that are capable of storing the sequences but the most common and reliable type is a list. To learn more about python you can join our Master Python programming course. A list is defined as a collection of values or items of different types. The items in the list are separated with a comma (,) and enclosed with the square brackets []. It is defined as follows: list1 = ['edureka', 'python', 2019]; list2 = [1, 2, 3, 4, 5 ]; list3 = ["a", "b", "c", "d"];If you want to learn Artificial Intelligence and Machine Learning in-depth, come to us and sign up for this Post Graduate Diploma AI and ML courses. ExplanationEverything in Python is an object, including lists. All objects have a header of some sort in the C implementation. Lists and other similar builtin objects with a "size" in Python, in particular, have an attribute called ob_size, where the number of elements in the object is cached. So checking the number of objects in a list is very fast. But if you're checking if list size is zero or not, don't use len - instead, put the list in a boolean context - it treated as False if empty, True otherwise. len(s)
len is implemented with __len__, from the data model docs: object.__len__(self)
And we can also see that __len__ is a method of lists: items.__len__()returns 3. IntroductionIn Python, you’ll be able to use a list function that creates a group that will be manipulated for your analysis. This collection of data is named a list object. While all methods are functions in Python, not all functions are methods. There’s a key difference between functions and methods in Python. Functions take objects as inputs while Methods in contrast act on objects. Image Source: Google Images Python offers the subsequent list functions:
|