numpy.isreal#

numpy.isreal(x)[source]#

Returns a bool array, where True if input element is real.

If element has complex type with zero imaginary part, the return value for that element is True.

Parameters:

xarray_like: Input array.

Returns:

outndarray, bool: Boolean array of same shape as x.

See also

iscomplex
isrealobj: Return True if x is not a complex type.

Notes

isreal may behave unexpectedly for string or object arrays (see examples)

Examples

>>> import numpy as np
>>> a = np.array([1+1j, 1+0j, 4.5, 3, 2, 2j], dtype=np.complex128)
>>> np.isreal(a)
array([False,  True,  True,  True,  True, False])

The function does not work on string arrays.

>>> a = np.array([2j, "a"], dtype=np.str_)
>>> np.isreal(a)  # returns the result of `"" == 0` currently.
array([False, False])

Returns True for all elements that either have no .imag attribute or for which that attribute is zero:

>>> a = np.array([1, "2", 3+4j], dtype=np.object_)
>>> np.isreal(a)
array([ True,  True,  False])