问题:从另一个文件导入变量?

如何将变量从一个文件导入到另一个文件?

示例:file1具有变量x1以及x2如何将其传递给file2

如何将所有变量从一个导入到另一个?

How can I import variables from one file to another?

example: file1 has the variables x1 and x2 how to pass them to file2?

How can I import all of the variables from one to another?


回答 0

from file1 import *  

将导入file1中的所有对象和方法

from file1 import *  

will import all objects and methods in file1


回答 1

导入file1内部file2

要从文件1导入所有变量而不泛洪文件2的命名空间,请使用:

import file1

#now use file1.x1, file2.x2, ... to access those variables

要将所有变量从file1导入到file2的命名空间(不推荐):

from file1 import *
#now use x1, x2..

文档

虽然from module import *在模块级别使用是有效的,但通常不是一个好主意。首先,它失去了Python否则具有的重要属性-您可以知道每个顶级名称在您喜欢的编辑器中通过简单的“搜索”功能定义的位置。如果某些模块增加了其他功能或类,将来还会给自己带来麻烦。

Import file1 inside file2:

To import all variables from file1 without flooding file2’s namespace, use:

import file1

#now use file1.x1, file2.x2, ... to access those variables

To import all variables from file1 to file2’s namespace( not recommended):

from file1 import *
#now use x1, x2..

From the docs:

While it is valid to use from module import * at module level it is usually a bad idea. For one, this loses an important property Python otherwise has — you can know where each toplevel name is defined by a simple “search” function in your favourite editor. You also open yourself to trouble in the future, if some module grows additional functions or classes.


回答 2

最好显式导入x1x2

from file1 import x1, x2

这样可以避免file1在中工作时与变量和函数发生不必要的命名空间冲突file2

但是,如果您确实需要,可以导入所有变量:

from file1 import * 

Best to import x1 and x2 explicitly:

from file1 import x1, x2

This allows you to avoid unnecessary namespace conflicts with variables and functions from file1 while working in file2.

But if you really want, you can import all the variables:

from file1 import * 

回答 3

实际上,使用以下命令导入变量并不完全相同:

from file1 import x1
print(x1)

import file1
print(file1.x1)

在导入时,x1和file1.x1的值完全相同,但它们不是相同的变量。例如,在file1中调用一个修改x1的函数,然后尝试从主文件中打印该变量:您将看不到修改后的值。

Actually this is not really the same to import a variable with:

from file1 import x1
print(x1)

and

import file1
print(file1.x1)

Altough at import time x1 and file1.x1 have the same value, they are not the same variables. For instance, call a function in file1 that modifies x1 and then try to print the variable from the main file: you will not see the modified value.


回答 4

马克的回答是正确的。实际上,您可以打印变量的内存地址,print(hex(id(libvar))并且可以看到地址是不同的。

# mylib.py
libvar = None
def lib_method():
    global libvar
    print(hex(id(libvar)))

# myapp.py
from mylib import libvar, lib_method
import mylib

lib_method()
print(hex(id(libvar)))
print(hex(id(mylib.libvar)))

Marc response is correct. Actually, you can print the memory address for the variables print(hex(id(libvar)) and you can see the addresses are different.

# mylib.py
libvar = None
def lib_method():
    global libvar
    print(hex(id(libvar)))

# myapp.py
from mylib import libvar, lib_method
import mylib

lib_method()
print(hex(id(libvar)))
print(hex(id(mylib.libvar)))

回答 5

script1.py

title="Hello world"

script2.py是我们使用script1变量的地方

方法1:

import script1
print(script1.title)

方法2:

from script1 import title
print(title)

script1.py

title="Hello world"

script2.py is where we using script1 variable

Method 1:

import script1
print(script1.title)

Method 2:

from script1 import title
print(title)

回答 6

Python您可以访问的其他文件的内容像,就好像它们
是某种库,比起像Java或任何OOP语言基础等语言,这是真的很酷;

这使得可以访问文件的内容或将其导入以对其进行处理或对其进行任何处理;这就是为什么Python高度首选数据科学和机器学习等语言的主要原因;

这是 project structure 这个

我从.env file哪里访问API links秘密密钥和秘密密钥所在的位置。

总体结构:

from <File-Name> import *

In Python you can access the contents of other files like as if they
are some kind of a library, compared to other languages like java or any oop base languages , This is really cool ;

This makes accessing the contents of the file or import it to to process it or to do anything with it ; And that is the Main reason why Python is highly preferred Language for Data Science and Machine Learning etc. ;

And this is the picture of project structure This

Where I am accessing variables from .env file where the API links and Secret keys reside .

General Structure:

from <File-Name> import *

回答 7

first.py:

a=5

second.py:

import first
print(first.a)

结果将是5。

first.py:

a=5

second.py:

import first
print(first.a)

The result will be 5.


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