Numpy Flashcards
(26 cards)
How do you import NumPy?
import numpy
How do you import NumPy with the alias ‘np’?
import numpy as np
How do you create a NumPy array from a list?
np.array([1, 2, 3])
How do you create a 1D array with values from 1 to 8?
np.arange(1, 9)
How do you add two arrays element-wise using a loop?
for i in range(len(A)): result.append(A[i] + B[i])
How do you add two arrays element-wise using NumPy vectorization?
np.array(A) + np.array(B)
How do you create a 2D array (matrix) from a list of lists?
np.array([[1,2,3], [4,5,6], [7,8,9]])
How do you check the shape of a NumPy array?
array.shape
How do you check the number of dimensions in a NumPy array?
array.ndim
How do you generate an array of 10 zeros?
np.zeros(10)
How do you generate an array of 10 ones?
np.ones(10)
How do you create an identity matrix of size 3x3?
np.eye(3)
How do you create an array of integers from 10 to 50?
np.arange(10, 51)
How do you create a 3x3 matrix with values 0 to 8?
np.arange(9).reshape(3, 3)
How do you access an element at row 2, column 3 of a matrix?
matrix[2, 3]
How do you filter values in an array greater than 10?
array[array > 10]
How do you compute the sum of all elements in a NumPy array?
np.sum(array)
How do you compute the standard deviation of a NumPy array?
np.std(array)
How do you generate 20 linearly spaced numbers between 0 and 1?
np.linspace(0, 1, 20)
How do you generate a random number between 0 and 1?
np.random.rand()
How do you generate a 3x3 array of random numbers?
np.random.rand(3, 3)
How do you generate 25 random numbers from a standard normal distribution?
np.random.randn(25)
How do you reshape a 1D array of length 9 into a 3x3 matrix?
array.reshape(3, 3)
