Why aren't the values from the for loop appending to the array?

May 21, 2023

I’m trying to append values from a for loop into a numpy array. While the values are correct, the array only returns none values. The values entered are from another numpy array.

import numpy as np
import matplotlib.pyplot as plt

j=np.array([14,15,16,16,16,22,22,24,24,25,25,25,25,25])
u=np.unique(j)


def P(age):
    sum=0
    for i in range(14):
        if j[i]==age:
            sum=sum+1
        else:
            sum=sum
    print(sum/14)
    
p = []
for i in range(6):
    p.append(P(u[i]))
p=np.array(p)
print(p)
print(type(p))

Output:

0.07142857142857142
0.07142857142857142
0.21428571428571427
0.14285714285714285
0.14285714285714285
0.35714285714285715
[None None None None None None]
<class 'numpy.ndarray'>

>Solution :

Function "P" doesn’t have a return function, hence equaling None each time.

def P(age):
    sum=0
    for i in range(14):
        if j[i]==age:
            sum=sum+1
        else:
            sum=sum
    print(sum/14)
    return sum/14

Shown here ^, you can return the sum.