为什么说fahr未定义？

Question

cel = float(5 / 9*(fahr - 32))

Traceback (most recent call last):
  File "<pyshell#31>", line 1, in <module>
    cel = float(5 / 9*(fahr - 32))
NameError: name 'fahr' is not defined

Answer 1

你得先写个:

    fahr=100
    #然后
    cel = float(5 / 9*(fahr - 32))

但是我估计你是想写个函数,所以你需要:

def f(fahr):
    cel = float(5 / 9*(fahr - 32))
    return cel