What is Python Numpy Array Dimension or Axis?

I’m beginner in Python & Numpy. Most tutorials I found seems for expert without really explaining the basic of it.

Even understanding what axis represents in Numpy array is difficult.

I have to read few tutorials and try it out myself before really understand it.

I will update it along with my growing knowledge.

1. Numpy Array Properties

1.1 Dimension

Important to know dimension because when to do concatenation, it will use axis or array dimension.

python array and axis - source oreilly
python array and axis – source oreilly

Row – in Numpy it is called axis 0

Columns – in Numpy it is called axis 1

Depth – in Numpy it is called axis 2

Python Example

import numpy as np

# Array with 1 dimension
A = np.array([1])
B = np.array([1,2])

print("A: ", A)
print("A dimensions: ", A.ndim)

print("B: ", B)
print("B dimensions: ", B.ndim)

# Array with 2 dimensions

C = np.array([[1,2], [3,4], [5,6]])

print("C: ", C)
print("C dimensions: ", C.ndim)

# Array with 3 dimensions

D = np.array([[[1,2], [3,4], [5,6]]])
print("D: ", D)
print("D dimensions: ", D.ndim)

Output

A:  [1]
A dimensions:  1
B:  [1 2]
B dimensions:  1
C:  [[1 2]
 [3 4]
 [5 6]]
C dimensions:  2
D:  [[[1 2]
  [3 4]
  [5 6]]]
D dimensions:  3

Snippet

References

https://www.datacamp.com/community/tutorials/python-numpy-tutorial
https://www.oreilly.com/library/view/elegant-scipy/9781491922927/ch01.html