Traditional configuration files are static in their nature. Using Python as configuration language will give the application user a dynaimc environment to configure the application.
Using Python's build in "execfile" this is very easy to implement.
Python, 36 lines
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Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 | # start --- config.ini ---
# --*-- python --*--
enemy = "Dr. No"
salary = 100
def tax(salary):
return salary * 0.2
bond = employee(id = "007", salary=salary * 2, tax=tax(salary * 2))
# end --- config.ini ---
# start --- readconf.py ---
class employee:
def __init__(self, id, salary, tax):
self.id = id
self.salary = salary
self.tax = tax
#FIXME: No error checking is done (to simplify code)
def read_conf(filename, optnames):
'''Read configuration file return elements hash'''
# Load file & eval
h = {}
execfile(filename, globals(), h)
# Get only what we want
options = {}
for item in h:
if isinstance(h[item], employee) or (item in optnames):
options[item] = h[item]
return options
# end --- readconf.py ---
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As we can see it is very easy to add new types of options. Option is selected is it is a known option or a subclass of an option class. You can change read_conf to get a list of known option classes and check of h[item].__class__ is one of them.
Known limitation: o Config file must be in Python syntax o Options names must be valid python variables o In unix if config file in in DOS format, compile will fail o Security, the user can place shutil.rmtree("/") somewhere ...
Calling a spade a spade. Good tip, but...
If it's not really an INI file, don't use the 'ini' extension.
What is the diference if I use execfile? I use something similar
mydict = {} execfile(filename,globals(),mydict)
Nice idea, BUT. try to write dialog driven software with check-boxes, drop-down-lists etc. to edit those ini-files.
Note that in Python3 execfile is gone, you need to do