pythonconstantspython-import

Importing a long list of constants to a Python file


In Python, is there an analogue of the C preprocessor statement such as?:

#define MY_CONSTANT 50

Also, I have a large list of constants I'd like to import to several classes. Is there an analogue of declaring the constants as a long sequence of statements like the above in a .py file and importing it to another .py file?

Edit.

The file Constants.py reads:

MY_CONSTANT_ONE = 50
MY_CONSTANT_TWO = 51

And myExample.py reads:

import sys
import os

import Constants

class myExample:
    def __init__(self):
        self.someValueOne = Constants.MY_CONSTANT_ONE + 1
        self.someValueTwo = Constants.MY_CONSTANT_TWO + 1

if __name__ == '__main__':
    x = MyClass()

Edit.

From the compiler,

NameError: "global name 'MY_CONSTANT_ONE' is not defined"

function init in myExample at line 13 self.someValueOne = Constants.MY_CONSTANT_ONE + 1 copy output Program exited with code #1 after 0.06 seconds.


Solution

  • Python isn't preprocessed. You can just create a file myconstants.py:

    MY_CONSTANT = 50
    

    And importing them will just work:

    import myconstants
    print myconstants.MY_CONSTANT * 2