python module __variable

sh$ cat module.py
#!/usr/bin/python

_var = 0
__var1 = 1
var2 = 2

def __func():
    print "__func"
func = __func

sh$ cat main.py
#!/usr/bin/python

import module

v = module.__var1
print v
v = module._var
print v
f = module.__func
f()

class test:
    def __init__(self):
        self.v = module._var
        # self.v = module.__var1    # (1)
        # self.f = module.__func    # (2)
        self.v = module.var2
        self.f = module.func        # (3)
    def run(self):
        print self.v
        self.f()

ti = test()
ti.run()

(1) 的输出：

sh$ python main.py
1
0
__func
Traceback (most recent call last):
  File "main.py", line 23, in ?
    ti = test()
  File "main.py", line 15, in __init__
    self.v = module.__var1
AttributeError: 'module' object has no attribute '_test__var1'

(2)的输出：

sh$ python main.py
1
0
__func
Traceback (most recent call last):
  File "main.py", line 23, in ?
    ti = test()
  File "main.py", line 16, in __init__
    self.f = module.__func
AttributeError: 'module' object has no attribute '_test__func'

在 module 层面都可以，但在 class 中 _var 可以但 __var 就不行，应该是和 class pseudo private 冲突了。当然 __var 是以 _ 开头，所以不能用 from module import __var 语法。