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numpy.isnan()用 Python

哎哎哎:# t0]https://www . geeksforgeeks . org/num py-isnan-python/

numpy.isnan() 函数逐元素测试它是否是 nan，并将结果作为布尔数组返回。 语法:

numpy.isnan(array [, out])

参数:

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.

返回:

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.

代码 1 :

# Python Program illustrating
# numpy.isnan() method

import numpy as geek 

print("Is NaN : ", geek.isnan(1), "\n")

print("Is NaN : ", geek.isnan(0), "\n")

# not a number
print("Is NaN : ", geek.isnan(geek.nan), "\n")

#  infinity
print("Is NaN : ", geek.isnan(geek.inf), "\n")

print("Is NaN : ", geek.isnan(geek.NINF), "\n") 

x = geek.array([-geek.inf, 0., geek.inf])
y = geek.array([2, 2, 2])
print("Checking for NaN : ", geek.isnan(x, y))

输出:

Is NaN :  False 

Is NaN :  False 

Is NaN :  True 

Is NaN :  False 

Is NaN :  False 

Checking for NaN :  [0 0 0]

代码 2 :

# Python Program illustrating
# numpy.isnan() method

import numpy as geek 

# Returns True/False value for each element 
b = geek.arange(20).reshape(5, 4)

print("\n",b)
print("\nIs NaN(Not a Number): \n", geek.isnan(b))

b = [[1j], 
     [geek.nan]]
print("\nIs NaN(Not a Number) : \n", geek.isnan(b))

输出:

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

Is NaN(Not a Number): 
 [[False False False False]
 [False False False False]
 [False False False False]
 [False False False False]
 [False False False False]]

Is NaN(Not a Number) : 
 [[False]
 [ True]]

参考文献: https://docs . scipy . org/doc/numpy-dev/reference/generated/numpy . isnan . html

注意: 这些代码不会在在线-ID 上运行。请在您的系统上运行它们来探索工作。 。 本文由 Mohit Gupta_OMG 供稿😀 。如果你喜欢 GeeksforGeeks 并想投稿，你也可以使用contribute.geeksforgeeks.org写一篇文章或者把你的文章邮寄到 contribute@geeksforgeeks.org。看到你的文章出现在极客博客主页上，帮助其他极客。

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