Basics

Given a file like this:

>>> f = open("/tmp/my_file.cfg", "w")
>>> _ = f.write("""
... CONFIG = {
...    "a" : {
...       "b" : 2,
...    }
... }""")
>>> f.close()

Obtaining a configuration object is done via:

>>> from infi.conf import Config
>>> c = Config.from_filename("/tmp/my_file.cfg")
>>> c.root.a.b
2

Loading From Other Sources

You can also load from string:

>>> c = Config.from_string("CONFIG = {'a' : 2}")
>>> c.root.a
2

Updating Paths

Setting paths is done by settings items:

>>> c['a'] = 3
>>> c.root.a
3

Setting paths that didn’t exist before is not allowed, unless you assign a config object:

>>> c['b'] = 3 #doctest: +IGNORE_EXCEPTION_DETAIL
Traceback (most recent call last):
 ...
CannotSetValue: Cannot set key 'b'

>>> c['b'] = Config(2)
>>> c.root.b
2

Assigning can also be done via the root proxy:

>>> c.root.a = 3
>>> c.root.a
3

Backing Up/Restoring

Whenever you want to preserve the configuration prior to a change and restore it later, you can do it with backup() and restore(). They work like a stack, so they push and pop states:

>>> c = Config({"value":2})
>>> c['value']
2
>>> c.backup()
>>> c['value'] = 3
>>> c['value']
3
>>> c.backup()
>>> c['value'] = 4
>>> c['value']
4
>>> c.restore()
>>> c['value']
3
>>> c.restore()
>>> c['value']
2

Utilities

>>> c = Config(dict(a=dict(b=dict(c=3))))
>>> from infi.conf.utils import assign_path
>>> assign_path(c, "a.b.c", 4)
>>> c.root.a.b.c
4

a.b.c=2

>>> from infi.conf.utils import assign_path_expression
>>> assign_path_expression(c, "a.b.c=2")
>>> c.root.a.b.c
'2'

>>> c['a']['b']['c'] = 3
>>> assign_path_expression(c, 'a.b.c=666', deduce_type=True)
>>> c.root.a.b.c
666