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Find the memory size of a NumPy array

In this post, we will see how to find the memory size of a NumPy array. So for finding the memory size of a NumPy array we are using following methods:

Using size and itemsize attributes of NumPy array

size: This attribute gives the number of elements present in the NumPy array.

itemsize: This attribute gives the memory size of one element of NumPy array in bytes.

Example 1:

Python3

 `# import library``import` `numpy as np` `# create a numpy 1d-array``x ``=` `np.array([``100``,``20``,``34``])` `print``(``"Size of the array: "``,``      ``x.size)` `print``(``"Memory size of one array element in bytes: "``,``      ``x.itemsize)` `# memory size of numpy array in bytes``print``(``"Memory size of numpy array in bytes:"``,``      ``x.size ``*` `x.itemsize)`

Output:

```Size of the array:  3
Memory size of one array element in bytes:  4
Memory size of numpy array in bytes: 12```

Example 2:

Python3

 `# import library``import` `numpy as np` `# create a numpy 2d-array``x ``=` `np.array([[``100``, ``20``, ``34``],``              ``[``300``, ``400``, ``600``]])` `print``(``"Size of the array: "``,``      ``x.size)` `print``(``"Memory size of one array element in bytes: "``,``      ``x.itemsize)` `# memory size of numpy array``print``(``"Memory size of numpy array in bytes:"``,``      ``x.size ``*` `x.itemsize)`

Output:

```Size of the array:  6
Length of one array element in bytes:  4
Memory size of numpy array in bytes: 24```

Using nbytes attribute of NumPy array.

nbytes: This attribute gives the total bytes consumed by the elements of the NumPy array.

Example 1:

Python3

 `import` `numpy as n``from` `sys ``import` `getsizeof` `l ``=` `[``0``] ``*` `10``a ``=` `np.array(l)` `print``(getsizeof(l))` `print``(l.nbytes)`

Output:

```136
40```

Example 2:

Python3

 `# import library``import` `numpy as np` `# create numpy 1d-array``x ``=` `np.array([``100``, ``20``, ``34``])` `print``(``"Memory size of a NumPy array:"``,``      ``x.nbytes)`

Output:

`Memory size of a NumPy array: 12`

Example 3:

Python3

 `# import library``import` `numpy as np` `# create numpy 2d-array``x ``=` `np.array([[``100``, ``20``, ``34``],``              ``[``300``, ``400``, ``600``]])` `print``(``"Memory size of a NumPy array:"``,``      ``x.nbytes)`

Output:

`Memory size of a NumPy array: 24`

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