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'''
Created on Jan 31, 2010
@author: tsitkova
'''
import re
import copy
import yaml
class ConfParser(object):
def __init__(self, path):
self.configuration = self._parse(path)
def walk(self):
for trio in self._walk(self.configuration):
yield trio
def _parse(self, path):
comment_pattern = re.compile(r'(\s*[#].*)')
section_pattern = re.compile(r'^\s*\[(?P<section>\w+)\]\s+$')
empty_pattern = re.compile(r'^\s*$')
equalsign_pattern = re.compile(r'=')
section = None
parser_stack = list()
result = dict()
value = None
f = open(path, 'r')
for (ln,line) in enumerate(f):
line = comment_pattern.sub('', line)
line = equalsign_pattern.sub(' = ',line,count=1)
if empty_pattern.match(line) is not None:
continue
m = section_pattern.match(line)
if m is not None:
section = m.group('section')
value = dict()
result[section] = value
continue
if section is None:
msg = 'Failed to determine section for line #%i' % ln
raise ValueError(msg)
try:
value = self._parseLine(value, line, parser_stack)
except:
print 'Error while parsing line %i: %s' % (ln+1, line)
raise
f.close()
if len(parser_stack):
raise 'Parsing error.'
return result
def _parseLine(self, value, content, stack):
token_pattern = re.compile(r'(?P<token>\S+)(?=\s+)')
attr = None
token_stack = list()
for m in token_pattern.finditer(content):
token = m.group('token')
if not self._validate(token):
raise ValueError('Invalid token %s' % token)
if token == '=':
if len(token_stack) == 0:
raise ValueError('Failed to find attribute.')
elif len(token_stack) == 1:
attr = token_stack.pop()
else:
value[attr] = token_stack[:-1]
attr = token_stack[-1]
token_stack = list()
elif token == '{':
if attr is None:
raise ValueError('Failed to find attribute.')
stack.append((attr,value))
value = dict()
elif token == '}':
if len(stack) == 0:
raise ValueError('Failed to parse: unbalanced braces')
if len(token_stack):
if attr is None:
raise ValueError('Missing attribute')
value[attr] = token_stack
attr = None
token_stack = list()
(attr,parent_value) = stack.pop()
parent_value[attr] = value
value = parent_value
else:
token_stack.append(token)
if len(token_stack):
if attr is None:
raise ValueError('Missing attribute')
value[attr] = token_stack
return value
def _validate(self, token):
result = True
for s in ['{','}']:
if s in token and s != token:
result = False
return result
def _walk(self, parsedData, path='root'):
dirs = list()
av = list()
for (key, value) in parsedData.iteritems():
if type(value) == dict:
new_path = path + '.' + key
for trio in self._walk(value, new_path):
yield trio
dirs.append(key)
else:
av.append((key,value))
yield (path, dirs, av)
class ConfParserTest(ConfParser):
def __init__(self):
self.conf_path = '../tests/krb5.conf'
super(ConfParserTest, self).__init__(self.conf_path)
def run_tests(self):
self._test_walk()
def _test_parse(self):
result = self._parse(self.conf_path)
print yaml.dump(result)
def _test_walk(self):
configuration = self._parse(self.conf_path)
for (path,dirs,av) in self.walk():
print path,dirs,av
if __name__ == '__main__':
tester = ConfParserTest()
tester.run_tests()
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