如何将来自不同python模块的功能用于另一个已定义的功能？

Question

这里我想在已定义的函数f（v）中使用模块FrenselIntegral.py中的c（v）和s（v）。

import FrenselIntegral as fi

v=0.0
u=0.2

def f(v): 0.5*((0.5-fi.c(v))**2+(0.5-fi.s(v))**2)

file=open("Straightedge diffraction pattern.txt","w")

for i in range (25):
   print>>file,v,f(v)
   v=v+u
file.close()

但是，输出是

Traceback (most recent call last):
  File "c:/Users/Shubhadeep/Desktop/New folder/Straightedge diffraction pattern.py", line 11, in <module>
    print>>file,v,f(v)
  File "c:/Users/Shubhadeep/Desktop/New folder/Straightedge diffraction pattern.py", line 4, in f
    def f(v): 0.5*((0.5-fi.c(v))**2+(0.5-fi.s(v))**2)
TypeError: unsupported operand type(s) for -: 'float' and 'NoneType'

Answer 1

该点看起来像fi.c（v）返回None。您可以检查v的哪些值给出该结果，或者只是避免返回None，例如：

import FrenselIntegral as fi

v=0.0
u=0.2

def f(v):
  if fi.c(v) is None or fi.s(v) is None:
    return 0
  else:
    return 0.5*((0.5-fi.c(v))**2+(0.5-fi.s(v))**2)

file=open("Straightedge diffraction pattern.txt","w")

for i in range (25):
   print>>file,v,f(v)
   v=v+u
file.close()