python - 一py文件中的中关于import的疑问?

Question

描述问题

地址见: autojump-中的import (第86-90行)

摘录部分如下(line: 86-90)

import copy as _copy
import os as _os
import re as _re
import sys as _sys
import textwrap as _textwrap

from gettext import gettext as _

为什么要将系统包重命名那样,不是多此一举么?

我的理解, 作为Python开发者,一般来说:

1. Python官方包也不算多

2. 浸淫久了,自然耳濡目染耳熟能详,一般不会去重名(虽然理论上会)

3. 用Python久了,导入哪个官方包,脑袋就会如同肌肉记忆一样

上下文环境

1. Linux

2. autojump

Answer 1

Here are the answers:

Why are modules imported as _<name> in another module?

To give a simple example, say there are modules a and b, where

# a.py
import os as _os
# import os

def cur_cwd():
    print _os.getcwd()

In addition, the module b.py in the same directory is as follows:

from a import * 
cur_cwd()
# print _os.getcwd()

You cannot use os or _os in b. If os is introduced directly in a.py, then os can be used in b.py.

Answer 2

• Generally speaking, it is indeed a bit unnecessary, but there may be cases where the names of user-defined packages, classes, or functions are the same as those of the standard library, but developers generally avoid this.

• One possibility is to hide the content of this code import from the files that reference this code. For example, if there is a main.py that imports this file, these standard library functions cannot be directly called in main.py, such as copy. copy() cannot be used directly, and it may be necessary to do so.