ndarray class attributes in NumPy

NumPy was created in 2005 by Travis Oliphant by combining features of Numarray into Numeric package.
Its main objects are multi-D array. It is a table of elements, indexed by a tuple of positive integers.

Axes : NumPy Dimensions
Rank : No. of axes

For e.g.
[[1, 0, 0],
[0, 1, 2]]

In this example: –

• 1st dimension has axis has length = 2
• 2nd dimension has axis has length = 3
• Rank = 2(2-Dimensional)

NumPy array class is known as ndarray.

Attributes of ndarray class :

• ndarray.ndim : Rank of array i.e. number of axes of the array.
• ndarray.shape : dimensions of array. This is a tuple of integers indicating the size of array.
  (n, m) : n(rows), m(column).
• ndarray.size : Total number of elements in the array (n * m).
• ndarray.dtype : An object describing the type of elements in the array. One can create or specify data types using standard Python types. e.g. numpy.int 32, numpy.float 64
• ndarray.itemsize : dtype/8 – Equivalent to ndarray.dtype.itemsize.
• ndarray.data : actual elements of the array are stored in this buffer.

Code : Python Program illustrating working of ndarray class :

# Python Program illustrating the working of ndarray class

import numpy as np

# Array declaration

a = np.arange(10).reshape(2, 5)

print("array : \n", a)

# use of ndarray.shape

print("\nndarray.shape : ", a.shape, "\n")

# use of ndarray.ndim

print("ndarray.ndim : ", a.ndim, "\n")

# use of ndarray.dtype

print("ndarray.dtype : ", a.dtype, "\n")

# use of ndarray.size

print("ndarray.size : ", a.size, "\n")

# use of ndarray.itemsize - dtype/8

print("ndarray.itemsize : ", a.itemsize, "\n")

Output :

array :
[[0 1 2 3 4]
[5 6 7 8 9]]

ndarray.shape :  (2, 5) 

ndarray.ndim :  2 

ndarray.dtype :  int32 

ndarray.size :  10 

ndarray.itemsize :  4 

By Mohit_OMG :)