The numpy.isfinite() function tests element-wise whether it is finite or not(not infinity or not Not a Number) and return the result as a boolean array. Syntax : 

numpy.isfinite(array [, out])

Parameters : 

array : [array_like]Input array or object whose elements, 
        we need to test for infinity
out   : [ndarray, optional]Output array placed with result.
       Its type is preserved and it must be of the right 
       shape to hold the output.

Return : 

boolean array containing the result

Code 1 : 

# Python Program illustrating
# numpy.isfinite() method
 
import numpy as geek 

print("Finite : ", geek.isfinite(1), "\n")

print("Finite : ", geek.isfinite(0), "\n")

# not a number
print("Finite : ", geek.isfinite(geek.nan), "\n")

#  infinity
print("Finite : ", geek.isfinite(geek.inf), "\n")

print("Finite : ", geek.isfinite(geek.NINF), "\n")  

Output : 

Finite :  True 

Finite :  True 

Finite :  False 

Finite :  False 

Finite :  False 

Code 2 : 

# Python Program illustrating
# numpy.isfinite() method
  
import numpy as geek 
 
# Returns True/False value for each element 
b = geek.arange(20).reshape(5, 4)
               
print("\n",b)
print("\nIs Finite : \n", geek.isfinite(b))


b = [[1j], 
     [geek.inf]]
print("\nIs Finite : \n", geek.isfinite(b))

Output : 

 [[ 0  1  2  3]
 [ 4  5  6  7]
 [ 8  9 10 11]
 [12 13 14 15]
 [16 17 18 19]]

Is Finite : 
 [[ True  True  True  True]
 [ True  True  True  True]
 [ True  True  True  True]
 [ True  True  True  True]
 [ True  True  True  True]]

Is Finite : 
 [[ True]
 [False]]

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