Python：如何导入所有变量？-Python:HowcanIimportallvariables?

56  

You gave the solution yourself: from a import * will work just fine. Python does not differentiate between functions and variables in this respect.

您自己给出了解决方案：从导入*将正常工作。 Python在这方面没有区分函数和变量。

>>> from a import *
>>> if name == "Michael" and age == 15:
...     print('Simple!')
...
Simple!

26  

Just for some context, most linters will flag from module import * with a warning, because it's prone to namespace collisions that will cause headaches down the road.

只是对于某些上下文，大多数linters将从模块导入*标记警告，因为它容易发生命名空间冲突，这将导致头痛。

Nobody has noted yet that, as an alternative, you can use the

没有人注意到，作为替代方案，你可以使用

from a import name, age

form and then use name and age directly (without the a. prefix). The from [module] import [identifiers] form is more future proof because you can easily see when one import will be overriding another.

表格，然后直接使用名称和年龄（没有a。前缀）。 from [module] import [identifier]表单更具未来性，因为您可以轻松查看一个导入何时覆盖另一个导入。

Also note that "variables" aren't different from functions in Python in terms of how they're addressed -- every identifier like name or sayBye is pointing at some kind of object. The identifier name is pointing at a string object, sayBye is pointing at a function object, and age is pointing at an integer object. When you tell Python:

另请注意，“变量”与Python中的函数没有区别，因为每个标识符如name或sayBye都指向某种对象。标识符名称指向字符串对象，sayBye指向函数对象，age指向整数对象。当你告诉Python时：

from a import name, age

you're saying "take those objects pointed at by name and age within module a and point at them in the current scope with the same identifiers".

你说的是“在模块a中按名称和年龄指向那些对象，并使用相同的标识符在当前范围内指向它们”。

Similarly, if you want to point at them with different identifiers on import, you can use the

同样，如果要在导入时使用不同的标识符指向它们，则可以使用

from a import sayBye as bidFarewell

form. The same function object gets pointed at, except in the current scope the identifier pointing at it is bidFarewell whereas in module a the identifier pointing at it is sayBye.

形成。指向相同的函数对象，除了在当前作用域中，指向它的标识符是bidFarewell，而在模块a中，指向它的标识符是sayBye。

12  

Like others have said,

像其他人说的那样，

from module import *

will also import the modules variables.

还将导入模块变量。

However, you need to understand that you are not importing variables, just references to objects. Assigning something else to the imported names in the importing module won't affect the other modules.

但是，您需要了解您不是导入变量，而是仅导入对象。在导入模块中为导入的名称分配其他内容不会影响其他模块。

Example: assume you have a module module.py containing the following code:

示例：假设您有一个模块module.py，其中包含以下代码：

a= 1
b= 2

Then you have two other modules, mod1.py and mod2.py which both do the following:

然后你有另外两个模块，mod1.py和mod2.py都执行以下操作：

from module import *

In each module, two names, a and b are created, pointing to the objects 1 and 2, respectively.

在每个模块中，创建两个名称a和b，分别指向对象1和2。

Now, if somewhere in mod1.py you assign something else to the global name a:

现在，如果mod1.py中的某个位置为全局名称指定了其他内容：

a= 3

the name a in module.py and the name a in mod2.py will still point to the object 1.

module.py中的名称a和mod2.py中的名称a仍将指向对象1。

So from module import * will work if you want read-only globals, but it won't work if you want read-write globals. If the latter, you're better off just importing import module and then either getting the value (module.a) or setting the value (module.a= …) prefixed by the module.

因此，如果您想要只读全局变量，那么从模块导入*将起作用，但如果您想要读写全局变量，它将无法工作。如果是后者，你最好只导入导入模块，然后获取值（module.a）或设置模块前缀的值（module.a = ...）。

7  

You didn't say this directly, but I'm assuming you're having trouble with manipulating these global variables.

你没有直接说出来，但我假设你在操纵这些全局变量时遇到了麻烦。

If you manipulate global variables from inside a function, you must declare them global

如果从函数内部操作全局变量，则必须将它们声明为全局变量

a = 10
def x():
   global a
   a = 15

print a
x()
print a

If you don't do that, then a = 15 will just create a local variable and assign it 15, while the global a stays 10

如果你不这样做，那么a = 15将只创建一个局部变量并将其分配15，而全局a保持10