The all() and any() functions on NumPy ndarray

Overview:

Given an n-dimensional matrix, its contents can be checked whether all of its elements evaluate to True or any of its elements evaluate to True.
The all() method of numpy.ndarray can be used to check whether all of the elements of an ndarray object evaluate to True.
The any() method of numpy.ndarray can be used to find whether any of the elements of an ndarray object evaluate to True.
These tests can be performed considering the n-dimensional array as a flat array or over a specific axis of the array.
When the axis is not specified these operations are performed on the whole array and when the axis is specified these operations are performed on the given axis.
While all() method performs a logical AND operation on the ndarray elements or the elements along the given axis of the ndarray, the any() method performs a logical OR operation.

Example: numpy.ndarray.all()

import numpy as np

# Create a 3 dimensional array

Array_3d = np.arange(9).reshape(3,3)

print("2 dimensional input array:")

print(Array_3d)

print("Return values from all():")

print("-------------------------")

print("When no axis is specified:")

print(Array_3d.all())

print("When no axis is specified and keepdims = True:")

print(Array_3d.all(keepdims=True))

print("When axis=0")

print(Array_3d.all(axis=0))

print("When axis=0, keepdims = True:")

print(Array_3d.all(axis=0, keepdims=True))

Output:

2 dimensional input array:

[[0 1 2]

[3 4 5]

[6 7 8]]

Return values from all():

-------------------------

When no axis is specified:

False

When no axis is specified and keepdims = True:

[[False]]

When axis=0

[False True True]

When axis=0, keepdims = True:

[[False True True]]

Example: numpy.ndarray.any()

import numpy as np

# Create a 3 dimensional array

Array_3d = np.arange(9).reshape(3,3)

print("2 dimensional input array:")

print(Array_3d)

print("Return values from any():")

print("-------------------------")

print("When no axis is specified:")

print(Array_3d.any())

print("When no axis is specified and keepdims = True:")

print(Array_3d.any(keepdims=True))

print("When axis=0")

print(Array_3d.any(axis=0))

print("When axis=0, keepdims = True:")

print(Array_3d.any(axis=0, keepdims=True))

Output:

2 dimensional input array:

[[0 1 2]

[3 4 5]

[6 7 8]]

Return values from any():

-------------------------

When no axis is specified:

True

When no axis is specified and keepdims = True:

[[ True]]

When axis=0

[ True True True]

When axis=0, keepdims = True:

[[ True True True]]