如何将功能从.py文件导入到另一个.py文件？

Question

I learned to use java functions before python functions, and generally I make a different classes for different "public static voids" so my main code regroup all of my functions. And when I wanted to do the same and I tried:

global def function():
print("String")

and

def global function():
print("String")

and some alternative ways (eg Make my function in another class, com back in my main and put "global function") but I still can't make global functions... So if anyone has the answer, just tell me!

Answer 1

In general you should build your Python projects as modules using __init__.py and setuptools . I usually just have a utilities type of module in my projects that contains all of my "global" functions. I then import that module wherever I need it and invoke the functions.

The functions can be defined normally with this approach, eg def my_function():

The standard in python is that any function which begins with an underline character is considered private while everything else would be considered public and accessible by anything/anyone.

Answer 2

Python is not Java. You can declare functions outside of any class declaration, and you can then import them in the current namespace in you want to.

Example: a file containing some functions (lets us call it glob_funcs.py)

def foo():
    return "Foo"

def bar(x):
    return "Bar >{}<".format(x)

How to import them:

from glob_funcs import foo, bar
print(foo())       # prints Foo
print(bar(foo())   # prints Bar >Foo<

Answer 3

When you create a class in python, its variables and methods are public by default. If you want to make your data protected you prefix the name with an underscore. If you want to make it private you prefix it with at least two underscores. For example:

class Something:
    def __init__(self):
        self.name = None # public variable
        self._grade = None # protected variable
        self.__pass = None # private variable