python count elements in array code example

Example 1: count similar values in list python

MyList = ["a", "b", "a", "c", "c", "a", "c"]

return my_dict = {i:MyList.count(i) for i in MyList}
# returns :
{'a': 3, 'c': 3, 'b': 1}
 # OR
from collections import Counter
return my_dict = dict(Counter(MyList))
# returns :   
{'a': 3, 'c': 3, 'b': 1}
# the both returns the same so it's up to you to choose the one you prefere ;)

Example 2: count values in array python

a = numpy.array([0, 3, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 1, 3, 4])
unique, counts = numpy.unique(a, return_counts=True)
dict(zip(unique, counts))

# {0: 7, 1: 4, 2: 1, 3: 2, 4: 1}

Example 3: python how to count all elements in a list

List = ["Elephant", "Snake", "Penguin"]

print(len(List))

#	With the 'len' function Python counts the amount of elements 
#	in a list (The length of the list).
#	In this case the output is '3' because there are 3 elements in the list.

Example 4: python how to count items in array

myArray = [1, 2, 3]
len(myArray)
#output
3

Example 5: python count of values in array

import numpy as np
y = np.array([0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1])
num_zeros = (y == 0).sum()
num_ones = (y == 1).sum()