Python NumPy Module Cheatsheet

Import NumPy Module

import numpy as np

NumPy Array

my_list = [92, 94, 88, 91, 87] 
numpy_array_from_list = np.array(my_list)

NumPy Array from CSV File

csv_file_name = 'test_2.csv'

numpy_array_from_csv_file = np.genfromtxt(csv_file_name, delimiter=',')

Operations on NumPy Arrays

numpy_array = np.array([1, 2, 3, 4, 5])
print(numpy_array + 1)
# returns [2, 3, 4, 5, 6]

print(numpy_array ** 2)
# returns [1, 2, 9, 16, 25]

Math Functions

Variance

import numpy as np

dividends_microsoft_eur = [0.6358, 0.6308, 0.6364, 0.6854, 0.6876, 0.7016, 0.7016, 0.7906]
variance_dividends_microsoft = np.var(dividends_microsoft_eur)

print('The variance of Microsoft stock dividends in 2023 and 2024 is', variance_dividends_microsoft)