numpy.isneginf() in Python

The numpy.isneginf() function tests element-wise whether it is negative infinity or not, and returns the result as a boolean array. 
Syntax :  

numpy.isneginf(array, y = None)

Parameters : 

array : [array_like]Input array or object whose elements, we need to test for infinity.
y : [array_like]A boolean array with the same shape and type as x to store the result.

Return : 

boolean array containing the result. For scalar input, the result is a new boolean with value
True if the input is positive or negative infinity; otherwise the value is False.
For array input, the result is a boolean array with the same shape as the input and the values
are True where the corresponding element of the input is positive or negative infinity; 
elsewhere the values are False.

Code 1 : 

Output : 

Negative : False 

Negative : False 

Negative : False 

Negative : False 

Negative : True 

Checking for negativity : [1 0 0]

Code 2 : 

Output : 

 [[ 0 1 2 3 4 5]
 [ 6 7 8 9 10 11]
 [12 13 14 15 16 17]]

Is Negative Infinity : 
 [[False False False False False False]
 [False False False False False False]
 [False False False False False False]]

Is Negative Infinity : 
 [[False]
 [ True]]

Note : 
These codes won't run on online IDE's. So please, run them on your systems to explore the working.
.