Numpy empty() to get array of input shape and type without initializing entries

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

Return array without initializing entries.

`shape`	Int, or sequence ( 2,3), shape of the output array
`dtype`	data-type( Optional ), Data Type of returned array.
`order`	{'C','F'} Optional, how the output is to be stored. C- style or Fortan style

Using shape

import numpy as np
ar=np.empty((1,3))
print(ar)

Output

[[5.e-324 5.e-324 5.e-324]]

Let us use different value for shape

ar=np.empty((4,2))
print(ar)

Output

[[3.02200272e-316 1.58101007e-322]
 [2.07955588e-312 1.16151774e-046]
 [4.81836453e-038 1.33694116e+165]
 [1.93417383e+184 1.33511316e-306]]

ar=np.empty((4,1))
print(ar)

Output

[[5.e-324]
 [5.e-324]
 [5.e-324]
 [0.e+000]]

We will try to return string dtype

import numpy as np
ar=np.empty(4,dtype=str)
print(ar) # ['' '' '' '']

Output

['' '' '' '']

dtype=float

ar=np.empty(4,dtype=float)
print(ar)

Output

[5.e-324 5.e-324 5.e-324 0.e+000]

dtype=int

ar=np.empty(4,dtype=int)
print(ar) # [1 1 1 0]

Output

[1 1 1 0]

ar=np.empty(4,dtype=np.int64)
print(ar) # [1 1 1 0]

Output

[1 1 1 0]