Python code coverage for Lib/packaging/fancy_getopt.py

#	count	content
1	n/a	"""Command line parsing machinery.
2	n/a
3	n/a	The FancyGetopt class is a Wrapper around the getopt module that
4	n/a	provides the following additional features:
5	n/a	* short and long options are tied together
6	n/a	* options have help strings, so fancy_getopt could potentially
7	n/a	create a complete usage summary
8	n/a	* options set attributes of a passed-in object.
9	n/a
10	n/a	It is used under the hood by the command classes. Do not use directly.
11	n/a	"""
12	n/a
13	n/a	import getopt
14	n/a	import re
15	n/a	import sys
16	n/a	import textwrap
17	n/a
18	n/a	from packaging.errors import PackagingGetoptError, PackagingArgError
19	n/a
20	n/a	# Much like command_re in packaging.core, this is close to but not quite
21	n/a	# the same as a Python NAME -- except, in the spirit of most GNU
22	n/a	# utilities, we use '-' in place of '_'. (The spirit of LISP lives on!)
23	n/a	# The similarities to NAME are again not a coincidence...
24	n/a	longopt_pat = r'[a-zA-Z](?:[a-zA-Z0-9-]*)'
25	n/a	longopt_re = re.compile(r'^%s$' % longopt_pat)
26	n/a
27	n/a	# For recognizing "negative alias" options, eg. "quiet=!verbose"
28	n/a	neg_alias_re = re.compile("^(%s)=!(%s)$" % (longopt_pat, longopt_pat))
29	n/a
30	n/a
31	n/a	class FancyGetopt:
32	n/a	"""Wrapper around the standard 'getopt()' module that provides some
33	n/a	handy extra functionality:
34	n/a	* short and long options are tied together
35	n/a	* options have help strings, and help text can be assembled
36	n/a	from them
37	n/a	* options set attributes of a passed-in object
38	n/a	* boolean options can have "negative aliases" -- eg. if
39	n/a	--quiet is the "negative alias" of --verbose, then "--quiet"
40	n/a	on the command line sets 'verbose' to false
41	n/a	"""
42	n/a
43	n/a	def __init__(self, option_table=None):
44	n/a
45	n/a	# The option table is (currently) a list of tuples. The
46	n/a	# tuples may have 3 or four values:
47	n/a	# (long_option, short_option, help_string [, repeatable])
48	n/a	# if an option takes an argument, its long_option should have '='
49	n/a	# appended; short_option should just be a single character, no ':'
50	n/a	# in any case. If a long_option doesn't have a corresponding
51	n/a	# short_option, short_option should be None. All option tuples
52	n/a	# must have long options.
53	n/a	self.option_table = option_table
54	n/a
55	n/a	# 'option_index' maps long option names to entries in the option
56	n/a	# table (ie. those 3-tuples).
57	n/a	self.option_index = {}
58	n/a	if self.option_table:
59	n/a	self._build_index()
60	n/a
61	n/a	# 'alias' records (duh) alias options; {'foo': 'bar'} means
62	n/a	# --foo is an alias for --bar
63	n/a	self.alias = {}
64	n/a
65	n/a	# 'negative_alias' keeps track of options that are the boolean
66	n/a	# opposite of some other option
67	n/a	self.negative_alias = {}
68	n/a
69	n/a	# These keep track of the information in the option table. We
70	n/a	# don't actually populate these structures until we're ready to
71	n/a	# parse the command line, since the 'option_table' passed in here
72	n/a	# isn't necessarily the final word.
73	n/a	self.short_opts = []
74	n/a	self.long_opts = []
75	n/a	self.short2long = {}
76	n/a	self.attr_name = {}
77	n/a	self.takes_arg = {}
78	n/a
79	n/a	# And 'option_order' is filled up in 'getopt()'; it records the
80	n/a	# original order of options (and their values) on the command line,
81	n/a	# but expands short options, converts aliases, etc.
82	n/a	self.option_order = []
83	n/a
84	n/a	def _build_index(self):
85	n/a	self.option_index.clear()
86	n/a	for option in self.option_table:
87	n/a	self.option_index[option[0]] = option
88	n/a
89	n/a	def set_option_table(self, option_table):
90	n/a	self.option_table = option_table
91	n/a	self._build_index()
92	n/a
93	n/a	def add_option(self, long_option, short_option=None, help_string=None):
94	n/a	if long_option in self.option_index:
95	n/a	raise PackagingGetoptError(
96	n/a	"option conflict: already an option '%s'" % long_option)
97	n/a	else:
98	n/a	option = (long_option, short_option, help_string)
99	n/a	self.option_table.append(option)
100	n/a	self.option_index[long_option] = option
101	n/a
102	n/a	def has_option(self, long_option):
103	n/a	"""Return true if the option table for this parser has an
104	n/a	option with long name 'long_option'."""
105	n/a	return long_option in self.option_index
106	n/a
107	n/a	def _check_alias_dict(self, aliases, what):
108	n/a	assert isinstance(aliases, dict)
109	n/a	for alias, opt in aliases.items():
110	n/a	if alias not in self.option_index:
111	n/a	raise PackagingGetoptError(
112	n/a	("invalid %s '%s': "
113	n/a	"option '%s' not defined") % (what, alias, alias))
114	n/a	if opt not in self.option_index:
115	n/a	raise PackagingGetoptError(
116	n/a	("invalid %s '%s': "
117	n/a	"aliased option '%s' not defined") % (what, alias, opt))
118	n/a
119	n/a	def set_aliases(self, alias):
120	n/a	"""Set the aliases for this option parser."""
121	n/a	self._check_alias_dict(alias, "alias")
122	n/a	self.alias = alias
123	n/a
124	n/a	def set_negative_aliases(self, negative_alias):
125	n/a	"""Set the negative aliases for this option parser.
126	n/a	'negative_alias' should be a dictionary mapping option names to
127	n/a	option names, both the key and value must already be defined
128	n/a	in the option table."""
129	n/a	self._check_alias_dict(negative_alias, "negative alias")
130	n/a	self.negative_alias = negative_alias
131	n/a
132	n/a	def _grok_option_table(self):
133	n/a	"""Populate the various data structures that keep tabs on the
134	n/a	option table. Called by 'getopt()' before it can do anything
135	n/a	worthwhile.
136	n/a	"""
137	n/a	self.long_opts = []
138	n/a	self.short_opts = []
139	n/a	self.short2long.clear()
140	n/a	self.repeat = {}
141	n/a
142	n/a	for option in self.option_table:
143	n/a	if len(option) == 3:
144	n/a	longopt, short, help = option
145	n/a	repeat = 0
146	n/a	elif len(option) == 4:
147	n/a	longopt, short, help, repeat = option
148	n/a	else:
149	n/a	# the option table is part of the code, so simply
150	n/a	# assert that it is correct
151	n/a	raise ValueError("invalid option tuple: %r" % option)
152	n/a
153	n/a	# Type- and value-check the option names
154	n/a	if not isinstance(longopt, str) or len(longopt) < 2:
155	n/a	raise PackagingGetoptError(
156	n/a	("invalid long option '%s': "
157	n/a	"must be a string of length >= 2") % longopt)
158	n/a
159	n/a	if (not ((short is None) or
160	n/a	(isinstance(short, str) and len(short) == 1))):
161	n/a	raise PackagingGetoptError(
162	n/a	("invalid short option '%s': "
163	n/a	"must be a single character or None") % short)
164	n/a
165	n/a	self.repeat[longopt] = repeat
166	n/a	self.long_opts.append(longopt)
167	n/a
168	n/a	if longopt[-1] == '=': # option takes an argument?
169	n/a	if short:
170	n/a	short = short + ':'
171	n/a	longopt = longopt[0:-1]
172	n/a	self.takes_arg[longopt] = 1
173	n/a	else:
174	n/a
175	n/a	# Is option is a "negative alias" for some other option (eg.
176	n/a	# "quiet" == "!verbose")?
177	n/a	alias_to = self.negative_alias.get(longopt)
178	n/a	if alias_to is not None:
179	n/a	if self.takes_arg[alias_to]:
180	n/a	raise PackagingGetoptError(
181	n/a	("invalid negative alias '%s': "
182	n/a	"aliased option '%s' takes a value") % \
183	n/a	(longopt, alias_to))
184	n/a
185	n/a	self.long_opts[-1] = longopt # XXX redundant?!
186	n/a	self.takes_arg[longopt] = 0
187	n/a
188	n/a	else:
189	n/a	self.takes_arg[longopt] = 0
190	n/a
191	n/a	# If this is an alias option, make sure its "takes arg" flag is
192	n/a	# the same as the option it's aliased to.
193	n/a	alias_to = self.alias.get(longopt)
194	n/a	if alias_to is not None:
195	n/a	if self.takes_arg[longopt] != self.takes_arg[alias_to]:
196	n/a	raise PackagingGetoptError(
197	n/a	("invalid alias '%s': inconsistent with "
198	n/a	"aliased option '%s' (one of them takes a value, "
199	n/a	"the other doesn't") % (longopt, alias_to))
200	n/a
201	n/a	# Now enforce some bondage on the long option name, so we can
202	n/a	# later translate it to an attribute name on some object. Have
203	n/a	# to do this a bit late to make sure we've removed any trailing
204	n/a	# '='.
205	n/a	if not longopt_re.match(longopt):
206	n/a	raise PackagingGetoptError(
207	n/a	("invalid long option name '%s' " +
208	n/a	"(must be letters, numbers, hyphens only") % longopt)
209	n/a
210	n/a	self.attr_name[longopt] = longopt.replace('-', '_')
211	n/a	if short:
212	n/a	self.short_opts.append(short)
213	n/a	self.short2long[short[0]] = longopt
214	n/a
215	n/a	def getopt(self, args=None, object=None):
216	n/a	"""Parse command-line options in args. Store as attributes on object.
217	n/a
218	n/a	If 'args' is None or not supplied, uses 'sys.argv[1:]'. If
219	n/a	'object' is None or not supplied, creates a new OptionDummy
220	n/a	object, stores option values there, and returns a tuple (args,
221	n/a	object). If 'object' is supplied, it is modified in place and
222	n/a	'getopt()' just returns 'args'; in both cases, the returned
223	n/a	'args' is a modified copy of the passed-in 'args' list, which
224	n/a	is left untouched.
225	n/a	"""
226	n/a	if args is None:
227	n/a	args = sys.argv[1:]
228	n/a	if object is None:
229	n/a	object = OptionDummy()
230	n/a	created_object = 1
231	n/a	else:
232	n/a	created_object = 0
233	n/a
234	n/a	self._grok_option_table()
235	n/a
236	n/a	short_opts = ' '.join(self.short_opts)
237	n/a
238	n/a	try:
239	n/a	opts, args = getopt.getopt(args, short_opts, self.long_opts)
240	n/a	except getopt.error as msg:
241	n/a	raise PackagingArgError(msg)
242	n/a
243	n/a	for opt, val in opts:
244	n/a	if len(opt) == 2 and opt[0] == '-': # it's a short option
245	n/a	opt = self.short2long[opt[1]]
246	n/a	else:
247	n/a	assert len(opt) > 2 and opt[:2] == '--'
248	n/a	opt = opt[2:]
249	n/a
250	n/a	alias = self.alias.get(opt)
251	n/a	if alias:
252	n/a	opt = alias
253	n/a
254	n/a	if not self.takes_arg[opt]: # boolean option?
255	n/a	assert val == '', "boolean option can't have value"
256	n/a	alias = self.negative_alias.get(opt)
257	n/a	if alias:
258	n/a	opt = alias
259	n/a	val = 0
260	n/a	else:
261	n/a	val = 1
262	n/a
263	n/a	attr = self.attr_name[opt]
264	n/a	# The only repeating option at the moment is 'verbose'.
265	n/a	# It has a negative option -q quiet, which should set verbose = 0.
266	n/a	if val and self.repeat.get(attr) is not None:
267	n/a	val = getattr(object, attr, 0) + 1
268	n/a	setattr(object, attr, val)
269	n/a	self.option_order.append((opt, val))
270	n/a
271	n/a	# for opts
272	n/a	if created_object:
273	n/a	return args, object
274	n/a	else:
275	n/a	return args
276	n/a
277	n/a	def get_option_order(self):
278	n/a	"""Returns the list of (option, value) tuples processed by the
279	n/a	previous run of 'getopt()'. Raises RuntimeError if
280	n/a	'getopt()' hasn't been called yet.
281	n/a	"""
282	n/a	if self.option_order is None:
283	n/a	raise RuntimeError("'getopt()' hasn't been called yet")
284	n/a	else:
285	n/a	return self.option_order
286	n/a
287	n/a	return self.option_order
288	n/a
289	n/a	def generate_help(self, header=None):
290	n/a	"""Generate help text (a list of strings, one per suggested line of
291	n/a	output) from the option table for this FancyGetopt object.
292	n/a	"""
293	n/a	# Blithely assume the option table is good: probably wouldn't call
294	n/a	# 'generate_help()' unless you've already called 'getopt()'.
295	n/a
296	n/a	# First pass: determine maximum length of long option names
297	n/a	max_opt = 0
298	n/a	for option in self.option_table:
299	n/a	longopt = option[0]
300	n/a	short = option[1]
301	n/a	l = len(longopt)
302	n/a	if longopt[-1] == '=':
303	n/a	l = l - 1
304	n/a	if short is not None:
305	n/a	l = l + 5 # " (-x)" where short == 'x'
306	n/a	if l > max_opt:
307	n/a	max_opt = l
308	n/a
309	n/a	opt_width = max_opt + 2 + 2 + 2 # room for indent + dashes + gutter
310	n/a
311	n/a	# Typical help block looks like this:
312	n/a	# --foo controls foonabulation
313	n/a	# Help block for longest option looks like this:
314	n/a	# --flimflam set the flim-flam level
315	n/a	# and with wrapped text:
316	n/a	# --flimflam set the flim-flam level (must be between
317	n/a	# 0 and 100, except on Tuesdays)
318	n/a	# Options with short names will have the short name shown (but
319	n/a	# it doesn't contribute to max_opt):
320	n/a	# --foo (-f) controls foonabulation
321	n/a	# If adding the short option would make the left column too wide,
322	n/a	# we push the explanation off to the next line
323	n/a	# --flimflam (-l)
324	n/a	# set the flim-flam level
325	n/a	# Important parameters:
326	n/a	# - 2 spaces before option block start lines
327	n/a	# - 2 dashes for each long option name
328	n/a	# - min. 2 spaces between option and explanation (gutter)
329	n/a	# - 5 characters (incl. space) for short option name
330	n/a
331	n/a	# Now generate lines of help text. (If 80 columns were good enough
332	n/a	# for Jesus, then 78 columns are good enough for me!)
333	n/a	line_width = 78
334	n/a	text_width = line_width - opt_width
335	n/a	big_indent = ' ' * opt_width
336	n/a	if header:
337	n/a	lines = [header]
338	n/a	else:
339	n/a	lines = ['Option summary:']
340	n/a
341	n/a	for option in self.option_table:
342	n/a	longopt, short, help = option[:3]
343	n/a	text = textwrap.wrap(help, text_width)
344	n/a
345	n/a	# Case 1: no short option at all (makes life easy)
346	n/a	if short is None:
347	n/a	if text:
348	n/a	lines.append(" --%-*s %s" % (max_opt, longopt, text[0]))
349	n/a	else:
350	n/a	lines.append(" --%-*s " % (max_opt, longopt))
351	n/a
352	n/a	# Case 2: we have a short option, so we have to include it
353	n/a	# just after the long option
354	n/a	else:
355	n/a	opt_names = "%s (-%s)" % (longopt, short)
356	n/a	if text:
357	n/a	lines.append(" --%-*s %s" %
358	n/a	(max_opt, opt_names, text[0]))
359	n/a	else:
360	n/a	lines.append(" --%-*s" % opt_names)
361	n/a
362	n/a	for l in text[1:]:
363	n/a	lines.append(big_indent + l)
364	n/a
365	n/a	return lines
366	n/a
367	n/a	def print_help(self, header=None, file=None):
368	n/a	if file is None:
369	n/a	file = sys.stdout
370	n/a	for line in self.generate_help(header):
371	n/a	file.write(line + "\n")
372	n/a
373	n/a
374	n/a	def fancy_getopt(options, negative_opt, object, args):
375	n/a	parser = FancyGetopt(options)
376	n/a	parser.set_negative_aliases(negative_opt)
377	n/a	return parser.getopt(args, object)
378	n/a
379	n/a
380	n/a	class OptionDummy:
381	n/a	"""Dummy class just used as a place to hold command-line option
382	n/a	values as instance attributes."""
383	n/a
384	n/a	def __init__(self, options=[]):
385	n/a	"""Create a new OptionDummy instance. The attributes listed in
386	n/a	'options' will be initialized to None."""
387	n/a	for opt in options:
388	n/a	setattr(self, opt, None)