Python：导入另一个.py文件

Question

I have a class and I want to import a def function by doing:

import <file>

but when I try to call it, it says that the def can not be found. I also tried:

from <file> import <def>

but then it says global name 'x' is not defined.

So how can I do this?

Edit:

Here is a example of what I am trying to do. In file1.py I have:

var = "hi"

class a:
  def __init__(self):
    self.b()

  import file2

a()

and in file2.py I have:

def b(self):
  print(var)

it is just giving me a error though.

Answer 1

import file2

loads the module file2 and binds it to the name file2 in the current namespace. b from file2 is available as file2.b , not b , so it isn't recognized as a method. You could fix it with

from file2 import b

which would load the module and assign the b function from that module to the name b . I wouldn't recommend it, though. Import file2 at top level and define a method that delegates to file2.b , or define a mixin superclass you can inherit from if you frequently need to use the same methods in unrelated classes. Importing a function to use it as a method is confusing, and it breaks if the function you're trying to use is implemented in C.