Modifying a variable in a module imported using from … import *

Question

Consider the following code:

#main.py
From toolsmodule import *
database = \"foo\"

#toolsmodule
database = \"mydatabase\"

As it seems, thi

Answer 1

Pythons variable names are just labels on variables. When you import * all those labels are local and when you then set the database, you just replace the local variable, not the one in toolsmodule. Hence, do this:

toolsmodule.py:

database = "original"

def printdatabase():
   print "Database is", database

And then run:

import toolsmodule
toolsmodule.database = "newdatabase"
toolsmodule.printdatabase()

The output is

Database is newdatabase

Note that if you then from ANOTHER module ALSO did an import * the change is not reflected.

In short: NEVER use from x import *. I don't know why all newbies persist in doing this despite all documentation I know of says that it's a bad idea.