Help for Basket Players code project.

Question

#Task : The given code includes a list of heights for various basketball players.
#You need to calculate and output how many players are in the range of one standard deviation from the mean.
#MyCode:
import math as mt
import numpy as np
a = np.array([180, 172, 178, 185, 190, 195, 192, 200, 210, 190])
mean = np.sum(a) / a.size
variance = np.sum((a-mean)**2)/a.size
std_deviation = mt.sqrt(variance)
result = 0
for x in a :
if x in range (int(mean-std_deviation),int(mean+std_deviation+1)) :
result+=1
print(result)
print(variance)
print(std_deviation )
#There's one case , it's hidden , where's the problem here ?

Answer 1

Ben Hamida Mohamed Amine

In the range() funtion, using int() on the calculated min value (mean - std) of 178.63 truncates it to the integer 178. This ends up making the range include the 178 value from the array, which is incorrect.

I don't think range() can be used here, since it only accepts integers and your actual range values are floats. Try using simple relational operations instead. Something like this:
if (x >= mean-std) and (x <= mean+std):
...

Also, you can compute the mean and std dev directly in numpy:
a.mean()
a.std()

To further shorten the code, you can make use of numpy's boolean masking instead of a loop:
a = np.array([...])
mask = (a>=a.mean()-a.std()) & (a<=a.mean()+a.std())
print(np.sum(mask))

Answer 2

Ben Hamida Mohamed Amine remember to mark Mozzy's answer as best to give XP credit.

This is my replacement for range to fix your code:
if abs(x - mean)<=std_deviation:

Answer 3

Thanks i solved it