Pyton Programming

Please help me describe the following code:
a) The structure
b) The overall feature it might provide
c) The mechanisms used to provide the feature.
class Config(object):
validKeys = [
'CompanyName', 'ExternalName',
'Hostname', 'Domain', 'SambaDomain'
]
def __init__(self):
profileLocator = open(os.path.join(Settings.BaseDir, 'currentProfile'))
profileName = profileLocator.read().replace(' ', '').strip()
self.configFile = os.path.join(Settings.BaseDir, 'profiles',
profileName)
self.cache = {}
self.cacheAge = 0
self.maxAge = 300
def __getattr__(self, name):
if name in self.validKeys:
configAge = os.stat(self.configFile).st_mtime
now = time.time()
#Setup conditions
stillValid = self.cacheAge == configAge
tooOld = (now self.
cacheAge) > self.maxAge
if self.cache and stillValid and not tooOld:
return self.cache[name]
# Read the file (full unbuffered)
cfo = open(self.configFile, 'rt')
self.cacheAge = os.stat(self.configFile).st_mtime
data = cfo.read()
cfo.close()
d = {}
exec data in d
self.cache = d
return self.cache[name]
else:
object.__getattr__(self, name, value)