How to remove some elements from an array in python?

[paul18fr]

I would have used numpy and np.where + np.delete (it has been fully detailled here after to see how it works); actually only lines 9-11-12-(22) are necessary.

import numpy as np

# a list is created first using numpy
N = 5_000
M = np.random.randint(-2, 10_000, size=(N)).tolist()

# it starts here
MaxNumber = 4_000
Mat = np.asarray(M)

Ind = np.where(Mat >= MaxNumber)
n = np.shape(Ind)[1]
print(f"There's {n} elements to remove")

Mat = np.delete(Mat, np.s_[Ind])

# you can of course sort the array if it's needed
Indexes = Mat.argsort()
MatSorted = Mat[Indexes]

# now you can go back to a list
M_new = MatSorted.tolist()