Question

我试图创建一个包含几个lambda函数的dict。 lambda函数是numpy百分位函数。但是我得到了奇怪的结果，好像所有lambda函数都包含np.percentile（x，q = 100）。

import numpy as np

d = {}
inc = 10

for i in range(0,101,inc):
    d[str(i)+'_perc'] = lambda x: np.percentile(x,q=i)

a = [1,2,3,4,5]

print(d)
print(d['10_perc'](a))
print(d['50_perc'](a))
print(d['90_perc'](a))

印刷产生：

{'50_perc': <function <lambda> at 0x2cb7b90>, '70_perc': <function <lambda> at 0x2cb77d0>, '40_perc': <function <lambda> at 0x2cb75f0>, '10_perc': <function <lambda> at 0x2cb7cf8>, '30_perc': <function <lambda> at 0x2cb7500>, '0_perc': <function <lambda> at 0x2cb7aa0>, '80_perc': <function <lambda> at 0x2cb78c0>, '20_perc': <function <lambda> at 0x2cb7a28>, '100_perc': <function <lambda> at 0x2cb7848>, '90_perc': <function <lambda> at 0x2cb7758>, '60_perc': <function <lambda> at 0x2cb7d70>}
5
5
5

好像所有lambda函数都被后续函数覆盖了......

Answer 1

找到解决方案：

后期绑定的东西，我不太明白。反正

def returnLambda(i):
    return lambda x: np.percentile(x,i)

for i in xrange(0,101,10): 
    d[str(i)+'_perc'] = returnLambda(i)
    print(i)

使用lambda函数作为dict值时发生奇怪的覆盖

1 个答案: