Python | Count occurrences of an element in a listGiven a list in Python and a number x, count number of occurrences of x in the given list. Show
Recommended: Please try your approach on {IDE} first, before moving on to the solution. Method 1 (Simple approach) Python3
Method 2 (Using count()) Python3
Method 2 (Using Counter()) Python3
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python-list Python Program to Count occurrences of an element in a listIn this tutorial, you will learn to count occurrences of an element in a list in Python. The List is an ordered set of values enclosed in square brackets [ ]. List stores some values called elements in it, which can be accessed by their particular index. Occurrence simply means the total number of times an element is present in the list. An element in a list can be repeated many times in the list. We have to write a program that will input an element from the user and then count and display the number of times that element is repeated in the list. Input: list=[2, 4, 1, 7, 9, 10, 12, 17, 1] n=1 Output: 2 ( 1 occurs 2 times in the list) Input: list=[3, 4, 5, 7, 8, 10, 2] n=1 Output: 0 (1 occurs 0 times in the list) Below are the three solutions:Fastest is using a for loop and storing it in a Dict. import time from collections import Counter def countElement(a): g = {} for i in a: if i in g: g[i] +=1 else: g[i] =1 return g z = [1,1,1,1,2,2,2,2,3,3,4,5,5,234,23,3,12,3,123,12,31,23,13,2,4,23,42,42,34,234,23,42,34,23,423,42,34,23,423,4,234,23,42,34,23,4,23,423,4,23,4] #Solution 1 - Faster st = time.monotonic() for i in range(1000000): b = countElement(z) et = time.monotonic() print(b) print('Simple for loop and storing it in dict - Duration: {}'.format(et - st)) #Solution 2 - Fast st = time.monotonic() for i in range(1000000): a = Counter(z) et = time.monotonic() print (a) print('Using collections.Counter - Duration: {}'.format(et - st)) #Solution 3 - Slow st = time.monotonic() for i in range(1000000): g = dict([(i, z.count(i)) for i in set(z)]) et = time.monotonic() print(g) print('Using list comprehension - Duration: {}'.format(et - st))Result #Solution 1 - Faster{1: 4, 2: 5, 3: 4, 4: 6, 5: 2, 234: 3, 23: 10, 12: 2, 123: 1, 31: 1, 13: 1, 42: 5, 34: 4, 423: 3} Simple for loop and storing it in dict - Duration: 12.032000000000153 #Solution 2 - FastCounter({23: 10, 4: 6, 2: 5, 42: 5, 1: 4, 3: 4, 34: 4, 234: 3, 423: 3, 5: 2, 12: 2, 123: 1, 31: 1, 13: 1}) Using collections.Counter - Duration: 15.889999999999418 #Solution 3 - Slow{1: 4, 2: 5, 3: 4, 4: 6, 5: 2, 34: 4, 423: 3, 234: 3, 42: 5, 12: 2, 13: 1, 23: 10, 123: 1, 31: 1} Using list comprehension - Duration: 33.0 Count Occurrences of Element in Python ListPython is well known for its easy syntax, fast implementation, and, most importantly, large support of multiple data structures. Lists are one of those data structures in python which helps to store large amounts of sequential data in a single variable. As huge data is stored under the same variable, it is sometimes quite difficult to manually identify whether the given element is present in the lists, and if yes, how many times. Therefore, in this article, we will study the various ways to count the number of occurrences in the list in python. To recall the concepts of python lists in detail, visit our article “3 Ways to Convert List to Tuple”. “count occurrences of each element in list python” Code Answer’scount number of occurrences of all elements in list python python by Important Ibex on Oct 08 2021 Comment 1 Source: www.kite.com how to find no of times a elements in list python python by Bst Barracuda on May 17 2020 Comment 8 python find number of occurrences in list python by Defiant Dogfish on May 30 2020 Comment 14 count occurrence in array python python by Merwanski 4 Add a Grepper Answer Python answers related to “count occurrences of each element in list python”
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