Question
Asked By – Ken
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:
#!/usr/bin/env python
# encoding: utf-8
"""
Constants.py
"""
MY_CONSTANT_ONE = 50
MY_CONSTANT_TWO = 51
And myExample.py
reads:
#!/usr/bin/env python
# encoding: utf-8
"""
myExample.py
"""
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.
Now we will see solution for issue: Importing a long list of constants to a Python file
Answer
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
This question is answered By – Thomas K
This answer is collected from stackoverflow and reviewed by FixPython community admins, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0