问题描述
在 Python 中，我不太清楚以下两行代码之间的区别:
In Python, I'm not really clear on the difference between the following two lines of code:
import X
或
from X import *
他们不是都只是从模块 X 中导入所有内容吗?有什么区别?
Don't they both just import everything from the module X? What's the difference?
推荐答案
import x 后，可以引用x中的东西，如x.something.在from x import *之后，你可以像something一样直接引用x中的东西.因为第二种形式将名称直接导入到本地命名空间中，所以如果您从许多模块导入内容，则可能会产生冲突.因此，不鼓励使用 from x import *.
After import x, you can refer to things in x like x.something. After from x import *, you can refer to things in x directly just as something. Because the second form imports the names directly into the local namespace, it creates the potential for conflicts if you import things from many modules. Therefore, the from x import * is discouraged.
您也可以执行 from x import something，它只将 something 导入本地命名空间，而不是 x 中的所有内容.这更好，因为如果您列出您导入的名称，您就可以确切地知道您要导入的内容，并且更容易避免名称冲突.
You can also do from x import something, which imports just the something into the local namespace, not everything in x. This is better because if you list the names you import, you know exactly what you are importing and it's easier to avoid name conflicts.
这篇关于“import X"与“import X"的区别和“从 X 导入 *"?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！