numpy.empty() in Python

The numpy module of Python provides a function called numpy.empty() . This function is used to create an array without initializing the entries of given shape and type.

Just like numpy.zeros() , the numpy.empty() function doesn't set the array values to zero, and it is quite faster than the numpy.zeros() . This function requires the user to set all the values in the array manually and should be used with caution.

Syntax

numpy.empty(shape, dtype=float, order='C')

Parameters:

shape: int or tuple of ints

This parameter defines the shape of the empty array, such as (3, 2) or (3, 3).

dtype: data-type(optional)

This parameter defines the data type, which is desired for the output array.

order: {'C', 'F'}(optional)

This parameter defines the order in which the multi-dimensional array is going to be stored either in row-major or column-major . By default, the order parameter is set to 'C' .

Returns:

This function returns the array of uninitialized data that have the shape, dtype, and order defined in the function.

Example 1:

import numpy as np x = np.empty([3, 2])

Output:

array([[7.56544226e-316, 2.07617768e-316],
       	[2.02322570e-316, 1.93432036e-316],
       	[1.93431918e-316, 1.93431799e-316]])

In the above code

  • We have imported numpy with alias name np.
  • We have declared the variable 'x' and assigned the returned value of the np.empty() function.
  • We have passed the shape in the function.
  • Lastly, we tried to print the value of 'x' and the difference between elements.
  • Example 2:

    import numpy as np x = np.empty([3, 3], dtype=float)

    Output:

    array([[ 2.94197848e+120, -2.70534020e+252, -4.25371363e+003],
           	[ 1.44429964e-088,  3.12897830e-053,  1.11313317e+253],
           	[-2.28920735e+294, -5.11507284e+039,  0.00000000e+000]])
    

    Example 3:

    import numpy as np x = np.empty([3, 3], dtype=float, order='C')

    Output:

    array([[ 2.94197848e+120, -2.70534020e+252, -4.25371363e+003],
           	[ 1.44429964e-088,  3.12897830e-053,  1.11313317e+253],
           	[-2.28920735e+294, -5.11507284e+039,  0.00000000e+000]]) 
    

    In the above code

  • We have imported numpy with alias name np.
  • We have declared the variable 'x' and assigned the returned value of the np.empty() function.
  • We have passed the shape, data-type, and order in the function.
  • Lastly, we tried to print the value of 'x' and the difference between elements.
  • In the output, it shows an array of uninitialized values of defined shape, data type, and order.

    Example 4:

    import numpy as np x = np.empty([3, 3], dtype=float, order='F')

    Output:

    array([[ 2.94197848e+120,  1.44429964e-088, -2.28920735e+294],
           	[-2.70534020e+252,  3.12897830e-053, -5.11507284e+039],
           	[-4.25371363e+003,  1.11313317e+253,  0.00000000e+000]])
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