Python | 單下劃線和雙下劃線可訪問性

環境: Python 3.10.4

1. 總結

先放總結

在實際開發過程中，強烈不推薦調用_或__開頭的內容，像__str__之類除外。

2. 類

2.1. 屬性

class Hello:
def __init__(self, one, two):
self._one = one
self.__two = two
h = Hello(1, 2)
print(h._one)
print(h.__two)

Output

1
Traceback (most recent call last):
File "/Users/yimt/Code/PycharmProjects/hello-python/hello.py", line 9, in <module>
print(h.__two)
AttributeError: 'Hello' object has no attribute '__two'

2.2. 方法

class Hello:
def _one(self):
print('one')
def __two(self):
print('two')
h = Hello()
h._one()
h.__two()

Output

Traceback (most recent call last):
File "/Users/yimt/Code/PycharmProjects/hello-python/learn.py", line 1, in <module>
import hello
File "/Users/yimt/Code/PycharmProjects/hello-python/hello.py", line 11, in <module>
h.__two()
AttributeError: 'Hello' object has no attribute '__two'
one

3. 模塊

程序正常執行

hello.py

def _one():
print('one')
def __two():
print('two')

main.py

import hello
hello._one()
hello.__two()

Output

one
two