NumPy Cheat Sheet

import numpy as npa = np.array([1, 2, 3])zeros = np.zeros((2, 3))ones  = np.ones((3, 3))range_arr = np.arange(0, 10, 2)lin = np.linspace(0, 1, 5)

a.shape        # (rows, cols)a.reshape(3, 2)a[0, :]        # First rowa[:, 1]        # Second columna[a > 2]       # Boolean indexing

b = a * 2c = a + bd = np.sqrt(a)sum_all = a.sum()mean_val = a.mean()

m = np.array([[1, 2], [3, 4]])v = np.array([10, 20])result = m + v  # v is "broadcast" across each row