Counting Duplicates in large Data Set

[paul18fr]

Hi

When speaking about duplicates for numbers, I'm alway thinking to "np.unique" => here bellow an example. Note at the same time Numpy is fast even for a huge array size.

Paul

import numpy as np

MyList=[0, 1, 10, 5, 2, 1, -1, 8, 2, 1, 5, 1, 1, 1, -1]
MyList=np.asarray(MyList)

UniqueList = np.unique(MyList, return_index=True, return_counts=True)

n = np.shape(UniqueList[0])[0]
for i in range(n):
    print(f"for {UniqueList[0][i]}  => {UniqueList[2][i]} occurence(s)")

Provinding:

Output:
for -1  => 2 occurence(s)
for 0  => 1 occurence(s)
for 1  => 6 occurence(s)
for 2  => 2 occurence(s)
for 5  => 2 occurence(s)
for 8  => 1 occurence(s)
for 10  => 1 occurence(s)