Python and numpy notes

import pandas as pd import numpy as np

python_list = [0,1,2,3,4,5,6,7,8,9] type(python_list) numpy_array = np.array(python_list) type(numpy_array)

numpy_array[::-1]

matrix = [[1,2,3], [4,5,6], [7,8,9]] print(matrix) print(type(matrix)) numpy_matrix = np.array(matrix) print(numpy_matrix) print(type(numpy_matrix))

numpy_matrix[1:,0:2]

float_array = np.array([1,2,3,4,5], dtype='float64') print(float_array) print(float_array.dtype) print(type(float_array))

astype_array = float_array.astype(np.float64) astype_array

boolean_array = astype_array.astype(np.bool_) boolean_array

string_array = np.array([1,2,3,4,5]) string_array = string_array.astype(np.string_) string_array

int_array = np.array([0,1,2,3,4,5]) int_array = int_array.astype(np.int8) int_array

scalar = np.array(42) print(scalar) scalar.ndim

vector = np.array([1,2,3]) print(vector) vector.ndim

three_dimensional_matrix = np.array([ [[1,2,3], [4,5,6], [7,8,9]], [[1,2,3], [4,5,6], [7,8,9]] ]) print(three_dimensional_matrix) three_dimensional_matrix.ndim

ten_vector = np.array([1,2,3],ndmin=10) print(ten_vector) ten_vector.ndim

expand = np.expand_dims(np.array([1,2,3]), axis=1) print(expand) expand.ndim

print(ten_vector, ten_vector.ndim) second_vector = np.squeeze(ten_vector) print(second_vector, second_vector.ndim)

np.arange(1,20,2)

np.zeros(3)

np.zeros((10,10))

np.ones((10,10))

np.linspace(1,10,100)

np.eye(4)

np.random.rand(5,5)

np.random.randint(1,20)

np.random.randint(1,100,(10,10))