1
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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
# Copyright 2012 OpenStack Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
class ParseError(Exception):
def __init__(self, message, line_no, line):
self.msg = message
self.line = line
self.line_no = line_no
def __str__(self):
return 'at line %d, %s: %r' % (self.line_no, self.msg, self.line)
class BaseParser(object):
PARSE_EXC = ParseError
def __init__(self):
super(BaseParser, self).__init__()
self.line_no = 0
def _assignment(self, key, value):
self.assignment(key, value)
return None, []
def _get_section(self, line):
if not line.endswith(']'):
return self.error_no_section_end_bracket(line)
if len(line) <= 2:
return self.error_no_section_name(line)
return line[1:-1]
def _split_key_value(self, line):
colon = line.find(':')
equal = line.find('=')
if colon < 0 and equal < 0:
return self.error_invalid_assignment(line)
if colon < 0 or (0 <= equal < colon):
key, value = line[:equal], line[equal + 1:]
else:
key, value = line[:colon], line[colon + 1:]
value = value.strip()
if value and value[0] == value[-1] and value.startswith(("\"", "'")):
value = value[1:-1]
return key.strip(), [value]
def _single_line_parse(self, line, key, value):
self.line_no += 1
if line.startswith(('#', ';')):
self.comment(line[1:].strip())
return key, value
active, _, comment = line.partition(';')
self.comment(comment.strip())
if not active:
# Blank line, ends multi-line values
if key:
key, value = self._assignment(key, value)
return key, value
if active.startswith((' ', '\t')):
# Continuation of previous assignment
if key is None:
return self.error_unexpected_continuation(line)
value.append(active.lstrip())
return key, value
if key:
# Flush previous assignment, if any
key, value = self._assignment(key, value)
if active.startswith('['):
# Section start
section = self._get_section(active)
if section:
self.new_section(section)
else:
key, value = self._split_key_value(active)
if not key:
return self.error_empty_key(line)
return key, value
def parse(self, line_iter=None):
if line_iter is None:
return
key = None
value = []
for line in line_iter:
key, value = self._single_line_parse(line, key, value)
if key:
# Flush previous assignment, if any
self._assignment(key, value)
def assignment(self, key, value):
"""Called when a full assignment is parsed."""
raise NotImplementedError()
def new_section(self, section):
"""Called when a new section is started."""
raise NotImplementedError()
def comment(self, comment):
"""Called when a comment is parsed."""
pass
def make_parser_error(self, template, line):
raise self.PARSE_EXC(template, self.line_no, line)
def error_invalid_assignment(self, line):
self.make_parser_error("No ':' or '=' found in assignment", line)
def error_empty_key(self, line):
self.make_parser_error('Key cannot be empty', line)
def error_unexpected_continuation(self, line):
self.make_parser_error('Unexpected continuation line', line)
def error_no_section_end_bracket(self, line):
self.make_parser_error('Invalid section (must end with ])', line)
def error_no_section_name(self, line):
self.make_parser_error('Empty section name', line)
class ConfigParser(BaseParser):
"""Parses a single config file, populating 'sections' to look like:
{'DEFAULT': {'key': [value, ...], ...},
...}
"""
def __init__(self, filename, sections):
super(ConfigParser, self).__init__()
self.filename = filename
self.sections = sections
self.section = None
def parse(self, line_iter=None):
with open(self.filename) as f:
return super(ConfigParser, self).parse(f)
def new_section(self, section):
self.section = section
self.sections.setdefault(self.section, [])
def assignment(self, key, value):
if not self.section:
raise self.error_no_section()
value = '\n'.join(value)
self.sections[self.section].append([key, value])
def error_no_section(self):
self.make_parser_error('Section must be started before assignment', '')
|
