numpy.select()函数| Python

numpy.select()()函数根据条件返回从选择列表中的元素绘制的数组。

Syntax : numpy.select(condlist, choicelist, default = 0)
Parameters :
condlist : [list of bool ndarrays] It determine from which array in choicelist the output elements are taken. When multiple conditions are satisfied, the first one encountered in condlist is used.
choicelist : [list of ndarrays] The list of arrays from which the output elements are taken. It has to be of the same length as condlist.
default : [scalar, optional] The element inserted in output when all conditions evaluate to False.
Return : [ndarray] An array drawn from elements in choicelist, depending on conditions.

代码#1：

# Python program explaining
# numpy.select() function
  
# importing numpy as geek 
import numpy as geek
  
arr = geek.arange(8)
  
condlist = [arr<3, arr>4]
choicelist = [arr, arr**3]
  
gfg = geek.select(condlist, choicelist)
  
print (gfg)

输出 ：

[  0, 1, 2, 0, 0, 125, 216, 343]

代码#2：

# Python program explaining
# numpy.select() function
  
# importing numpy as geek 
import numpy as geek
  
arr = geek.arange(8)
  
condlist = [arr<4, arr>6]
choicelist = [arr, arr**2]
  
gfg = geek.select(condlist, choicelist)
  
print (gfg)

输出 ：

[ 0, 1, 2, 3, 0, 0, 0, 49]