动态导入有两种：

1 __main__():

f="demo.A"

aa=__main__(f)

aa.A.t()

2 import importlib:

import importlib

f="demo.A"

aa=importlib.import_module(f)

aa.t()

全局变量使用：

global_list.py:

size=None

A.py:

from demo import global_list

global_list.size=101

from demo.B import *

t()

B.py:

from demo import global_list

def t():

global_list.size+=100

print(global_list.size)

类似的php

A.php:

$size=101

include_once "./B.php"

t();

echo $size;

B.php:

function t(){

 global $size;

 $size+=100;

 echo $size;

}