`numpy.fft:rfft2`

Signature

   def     rfft2 (    a    ,    s    =  None   ,    axes    =  (-2, -1)   ,    norm    =  None   ,    out    =  None     )

Compute the 2-dimensional FFT of a real array.

a : array: Input array, taken to be real.
s : sequence of ints, optional: Shape of the FFT.
versionchanged 2.0
If it is -1, the whole input is used (no padding/trimming).
deprecated 2.0
If s is not None, axes must not be None either.
deprecated 2.0
s must contain only int s, not None values. None values currently mean that the default value for n is used in the corresponding 1-D transform, but this behaviour is deprecated.
axes : sequence of ints, optional: Axes over which to compute the FFT. Default: (-2, -1).
deprecated 2.0
If s is specified, the corresponding axes to be transformed must not be None.
norm : {"backward", "ortho", "forward"}, optional: Normalization mode (see numpy.fft). Default is "backward". Indicates which direction of the forward/backward pair of transforms is scaled and with what normalization factor.
versionadded 1.20.0
The "backward", "forward" values were added.
out : complex ndarray, optional: If provided, the result will be placed in this array. It should be of the appropriate shape and dtype for the last inverse transform. incompatible with passing in all but the trivial s).
versionadded 2.0.0

This is really just rfftn with different default behavior. For more details see rfftn.

import numpy as np
a = np.mgrid[:5, :5][0]
np.fft.rfft2(a)