Importing variables from another file?

PythonFileVariablesImport

Python Problem Overview


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?

Python Solutions


Solution 1 - Python

from file1 import *  

will import all objects and methods in file1

Solution 2 - Python

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.

Solution 3 - Python

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 * 

Solution 4 - Python

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.

Solution 5 - Python

first.py:

a=5

second.py:

import first
print(first.a)

The result will be 5.

Solution 6 - Python

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)

Solution 7 - Python

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)))

Attributions

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Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionSome kidView Question on Stackoverflow
Solution 1 - PythonennuikillerView Answer on Stackoverflow
Solution 2 - PythonAshwini ChaudharyView Answer on Stackoverflow
Solution 3 - PythonChris RedfordView Answer on Stackoverflow
Solution 4 - PythonMarc RechtéView Answer on Stackoverflow
Solution 5 - Python陳仲肯View Answer on Stackoverflow
Solution 6 - PythonRaviView Answer on Stackoverflow
Solution 7 - PythonLei ZView Answer on Stackoverflow