python (3.11.7)
1 """distutils.fancy_getopt
2
3 Wrapper around the standard getopt module that provides the following
4 additional features:
5 * short and long options are tied together
6 * options have help strings, so fancy_getopt could potentially
7 create a complete usage summary
8 * options set attributes of a passed-in object
9 """
10
11 import sys, string, re
12 import getopt
13 from distutils.errors import *
14
15 # Much like command_re in distutils.core, this is close to but not quite
16 # the same as a Python NAME -- except, in the spirit of most GNU
17 # utilities, we use '-' in place of '_'. (The spirit of LISP lives on!)
18 # The similarities to NAME are again not a coincidence...
19 longopt_pat = r'[a-zA-Z](?:[a-zA-Z0-9-]*)'
20 longopt_re = re.compile(r'^%s$' % longopt_pat)
21
22 # For recognizing "negative alias" options, eg. "quiet=!verbose"
23 neg_alias_re = re.compile("^(%s)=!(%s)$" % (longopt_pat, longopt_pat))
24
25 # This is used to translate long options to legitimate Python identifiers
26 # (for use as attributes of some object).
27 longopt_xlate = str.maketrans('-', '_')
28
29 class ESC[4;38;5;81mFancyGetopt:
30 """Wrapper around the standard 'getopt()' module that provides some
31 handy extra functionality:
32 * short and long options are tied together
33 * options have help strings, and help text can be assembled
34 from them
35 * options set attributes of a passed-in object
36 * boolean options can have "negative aliases" -- eg. if
37 --quiet is the "negative alias" of --verbose, then "--quiet"
38 on the command line sets 'verbose' to false
39 """
40
41 def __init__(self, option_table=None):
42 # The option table is (currently) a list of tuples. The
43 # tuples may have 3 or four values:
44 # (long_option, short_option, help_string [, repeatable])
45 # if an option takes an argument, its long_option should have '='
46 # appended; short_option should just be a single character, no ':'
47 # in any case. If a long_option doesn't have a corresponding
48 # short_option, short_option should be None. All option tuples
49 # must have long options.
50 self.option_table = option_table
51
52 # 'option_index' maps long option names to entries in the option
53 # table (ie. those 3-tuples).
54 self.option_index = {}
55 if self.option_table:
56 self._build_index()
57
58 # 'alias' records (duh) alias options; {'foo': 'bar'} means
59 # --foo is an alias for --bar
60 self.alias = {}
61
62 # 'negative_alias' keeps track of options that are the boolean
63 # opposite of some other option
64 self.negative_alias = {}
65
66 # These keep track of the information in the option table. We
67 # don't actually populate these structures until we're ready to
68 # parse the command-line, since the 'option_table' passed in here
69 # isn't necessarily the final word.
70 self.short_opts = []
71 self.long_opts = []
72 self.short2long = {}
73 self.attr_name = {}
74 self.takes_arg = {}
75
76 # And 'option_order' is filled up in 'getopt()'; it records the
77 # original order of options (and their values) on the command-line,
78 # but expands short options, converts aliases, etc.
79 self.option_order = []
80
81 def _build_index(self):
82 self.option_index.clear()
83 for option in self.option_table:
84 self.option_index[option[0]] = option
85
86 def set_option_table(self, option_table):
87 self.option_table = option_table
88 self._build_index()
89
90 def add_option(self, long_option, short_option=None, help_string=None):
91 if long_option in self.option_index:
92 raise DistutilsGetoptError(
93 "option conflict: already an option '%s'" % long_option)
94 else:
95 option = (long_option, short_option, help_string)
96 self.option_table.append(option)
97 self.option_index[long_option] = option
98
99 def has_option(self, long_option):
100 """Return true if the option table for this parser has an
101 option with long name 'long_option'."""
102 return long_option in self.option_index
103
104 def get_attr_name(self, long_option):
105 """Translate long option name 'long_option' to the form it
106 has as an attribute of some object: ie., translate hyphens
107 to underscores."""
108 return long_option.translate(longopt_xlate)
109
110 def _check_alias_dict(self, aliases, what):
111 assert isinstance(aliases, dict)
112 for (alias, opt) in aliases.items():
113 if alias not in self.option_index:
114 raise DistutilsGetoptError(("invalid %s '%s': "
115 "option '%s' not defined") % (what, alias, alias))
116 if opt not in self.option_index:
117 raise DistutilsGetoptError(("invalid %s '%s': "
118 "aliased option '%s' not defined") % (what, alias, opt))
119
120 def set_aliases(self, alias):
121 """Set the aliases for this option parser."""
122 self._check_alias_dict(alias, "alias")
123 self.alias = alias
124
125 def set_negative_aliases(self, negative_alias):
126 """Set the negative aliases for this option parser.
127 'negative_alias' should be a dictionary mapping option names to
128 option names, both the key and value must already be defined
129 in the option table."""
130 self._check_alias_dict(negative_alias, "negative alias")
131 self.negative_alias = negative_alias
132
133 def _grok_option_table(self):
134 """Populate the various data structures that keep tabs on the
135 option table. Called by 'getopt()' before it can do anything
136 worthwhile.
137 """
138 self.long_opts = []
139 self.short_opts = []
140 self.short2long.clear()
141 self.repeat = {}
142
143 for option in self.option_table:
144 if len(option) == 3:
145 long, short, help = option
146 repeat = 0
147 elif len(option) == 4:
148 long, short, help, repeat = option
149 else:
150 # the option table is part of the code, so simply
151 # assert that it is correct
152 raise ValueError("invalid option tuple: %r" % (option,))
153
154 # Type- and value-check the option names
155 if not isinstance(long, str) or len(long) < 2:
156 raise DistutilsGetoptError(("invalid long option '%s': "
157 "must be a string of length >= 2") % long)
158
159 if (not ((short is None) or
160 (isinstance(short, str) and len(short) == 1))):
161 raise DistutilsGetoptError("invalid short option '%s': "
162 "must a single character or None" % short)
163
164 self.repeat[long] = repeat
165 self.long_opts.append(long)
166
167 if long[-1] == '=': # option takes an argument?
168 if short: short = short + ':'
169 long = long[0:-1]
170 self.takes_arg[long] = 1
171 else:
172 # Is option is a "negative alias" for some other option (eg.
173 # "quiet" == "!verbose")?
174 alias_to = self.negative_alias.get(long)
175 if alias_to is not None:
176 if self.takes_arg[alias_to]:
177 raise DistutilsGetoptError(
178 "invalid negative alias '%s': "
179 "aliased option '%s' takes a value"
180 % (long, alias_to))
181
182 self.long_opts[-1] = long # XXX redundant?!
183 self.takes_arg[long] = 0
184
185 # If this is an alias option, make sure its "takes arg" flag is
186 # the same as the option it's aliased to.
187 alias_to = self.alias.get(long)
188 if alias_to is not None:
189 if self.takes_arg[long] != self.takes_arg[alias_to]:
190 raise DistutilsGetoptError(
191 "invalid alias '%s': inconsistent with "
192 "aliased option '%s' (one of them takes a value, "
193 "the other doesn't"
194 % (long, alias_to))
195
196 # Now enforce some bondage on the long option name, so we can
197 # later translate it to an attribute name on some object. Have
198 # to do this a bit late to make sure we've removed any trailing
199 # '='.
200 if not longopt_re.match(long):
201 raise DistutilsGetoptError(
202 "invalid long option name '%s' "
203 "(must be letters, numbers, hyphens only" % long)
204
205 self.attr_name[long] = self.get_attr_name(long)
206 if short:
207 self.short_opts.append(short)
208 self.short2long[short[0]] = long
209
210 def getopt(self, args=None, object=None):
211 """Parse command-line options in args. Store as attributes on object.
212
213 If 'args' is None or not supplied, uses 'sys.argv[1:]'. If
214 'object' is None or not supplied, creates a new OptionDummy
215 object, stores option values there, and returns a tuple (args,
216 object). If 'object' is supplied, it is modified in place and
217 'getopt()' just returns 'args'; in both cases, the returned
218 'args' is a modified copy of the passed-in 'args' list, which
219 is left untouched.
220 """
221 if args is None:
222 args = sys.argv[1:]
223 if object is None:
224 object = OptionDummy()
225 created_object = True
226 else:
227 created_object = False
228
229 self._grok_option_table()
230
231 short_opts = ' '.join(self.short_opts)
232 try:
233 opts, args = getopt.getopt(args, short_opts, self.long_opts)
234 except getopt.error as msg:
235 raise DistutilsArgError(msg)
236
237 for opt, val in opts:
238 if len(opt) == 2 and opt[0] == '-': # it's a short option
239 opt = self.short2long[opt[1]]
240 else:
241 assert len(opt) > 2 and opt[:2] == '--'
242 opt = opt[2:]
243
244 alias = self.alias.get(opt)
245 if alias:
246 opt = alias
247
248 if not self.takes_arg[opt]: # boolean option?
249 assert val == '', "boolean option can't have value"
250 alias = self.negative_alias.get(opt)
251 if alias:
252 opt = alias
253 val = 0
254 else:
255 val = 1
256
257 attr = self.attr_name[opt]
258 # The only repeating option at the moment is 'verbose'.
259 # It has a negative option -q quiet, which should set verbose = 0.
260 if val and self.repeat.get(attr) is not None:
261 val = getattr(object, attr, 0) + 1
262 setattr(object, attr, val)
263 self.option_order.append((opt, val))
264
265 # for opts
266 if created_object:
267 return args, object
268 else:
269 return args
270
271 def get_option_order(self):
272 """Returns the list of (option, value) tuples processed by the
273 previous run of 'getopt()'. Raises RuntimeError if
274 'getopt()' hasn't been called yet.
275 """
276 if self.option_order is None:
277 raise RuntimeError("'getopt()' hasn't been called yet")
278 else:
279 return self.option_order
280
281 def generate_help(self, header=None):
282 """Generate help text (a list of strings, one per suggested line of
283 output) from the option table for this FancyGetopt object.
284 """
285 # Blithely assume the option table is good: probably wouldn't call
286 # 'generate_help()' unless you've already called 'getopt()'.
287
288 # First pass: determine maximum length of long option names
289 max_opt = 0
290 for option in self.option_table:
291 long = option[0]
292 short = option[1]
293 l = len(long)
294 if long[-1] == '=':
295 l = l - 1
296 if short is not None:
297 l = l + 5 # " (-x)" where short == 'x'
298 if l > max_opt:
299 max_opt = l
300
301 opt_width = max_opt + 2 + 2 + 2 # room for indent + dashes + gutter
302
303 # Typical help block looks like this:
304 # --foo controls foonabulation
305 # Help block for longest option looks like this:
306 # --flimflam set the flim-flam level
307 # and with wrapped text:
308 # --flimflam set the flim-flam level (must be between
309 # 0 and 100, except on Tuesdays)
310 # Options with short names will have the short name shown (but
311 # it doesn't contribute to max_opt):
312 # --foo (-f) controls foonabulation
313 # If adding the short option would make the left column too wide,
314 # we push the explanation off to the next line
315 # --flimflam (-l)
316 # set the flim-flam level
317 # Important parameters:
318 # - 2 spaces before option block start lines
319 # - 2 dashes for each long option name
320 # - min. 2 spaces between option and explanation (gutter)
321 # - 5 characters (incl. space) for short option name
322
323 # Now generate lines of help text. (If 80 columns were good enough
324 # for Jesus, then 78 columns are good enough for me!)
325 line_width = 78
326 text_width = line_width - opt_width
327 big_indent = ' ' * opt_width
328 if header:
329 lines = [header]
330 else:
331 lines = ['Option summary:']
332
333 for option in self.option_table:
334 long, short, help = option[:3]
335 text = wrap_text(help, text_width)
336 if long[-1] == '=':
337 long = long[0:-1]
338
339 # Case 1: no short option at all (makes life easy)
340 if short is None:
341 if text:
342 lines.append(" --%-*s %s" % (max_opt, long, text[0]))
343 else:
344 lines.append(" --%-*s " % (max_opt, long))
345
346 # Case 2: we have a short option, so we have to include it
347 # just after the long option
348 else:
349 opt_names = "%s (-%s)" % (long, short)
350 if text:
351 lines.append(" --%-*s %s" %
352 (max_opt, opt_names, text[0]))
353 else:
354 lines.append(" --%-*s" % opt_names)
355
356 for l in text[1:]:
357 lines.append(big_indent + l)
358 return lines
359
360 def print_help(self, header=None, file=None):
361 if file is None:
362 file = sys.stdout
363 for line in self.generate_help(header):
364 file.write(line + "\n")
365
366
367 def fancy_getopt(options, negative_opt, object, args):
368 parser = FancyGetopt(options)
369 parser.set_negative_aliases(negative_opt)
370 return parser.getopt(args, object)
371
372
373 WS_TRANS = {ord(_wschar) : ' ' for _wschar in string.whitespace}
374
375 def wrap_text(text, width):
376 """wrap_text(text : string, width : int) -> [string]
377
378 Split 'text' into multiple lines of no more than 'width' characters
379 each, and return the list of strings that results.
380 """
381 if text is None:
382 return []
383 if len(text) <= width:
384 return [text]
385
386 text = text.expandtabs()
387 text = text.translate(WS_TRANS)
388 chunks = re.split(r'( +|-+)', text)
389 chunks = [ch for ch in chunks if ch] # ' - ' results in empty strings
390 lines = []
391
392 while chunks:
393 cur_line = [] # list of chunks (to-be-joined)
394 cur_len = 0 # length of current line
395
396 while chunks:
397 l = len(chunks[0])
398 if cur_len + l <= width: # can squeeze (at least) this chunk in
399 cur_line.append(chunks[0])
400 del chunks[0]
401 cur_len = cur_len + l
402 else: # this line is full
403 # drop last chunk if all space
404 if cur_line and cur_line[-1][0] == ' ':
405 del cur_line[-1]
406 break
407
408 if chunks: # any chunks left to process?
409 # if the current line is still empty, then we had a single
410 # chunk that's too big too fit on a line -- so we break
411 # down and break it up at the line width
412 if cur_len == 0:
413 cur_line.append(chunks[0][0:width])
414 chunks[0] = chunks[0][width:]
415
416 # all-whitespace chunks at the end of a line can be discarded
417 # (and we know from the re.split above that if a chunk has
418 # *any* whitespace, it is *all* whitespace)
419 if chunks[0][0] == ' ':
420 del chunks[0]
421
422 # and store this line in the list-of-all-lines -- as a single
423 # string, of course!
424 lines.append(''.join(cur_line))
425
426 return lines
427
428
429 def translate_longopt(opt):
430 """Convert a long option name to a valid Python identifier by
431 changing "-" to "_".
432 """
433 return opt.translate(longopt_xlate)
434
435
436 class ESC[4;38;5;81mOptionDummy:
437 """Dummy class just used as a place to hold command-line option
438 values as instance attributes."""
439
440 def __init__(self, options=[]):
441 """Create a new OptionDummy instance. The attributes listed in
442 'options' will be initialized to None."""
443 for opt in options:
444 setattr(self, opt, None)
445
446
447 if __name__ == "__main__":
448 text = """\
449 Tra-la-la, supercalifragilisticexpialidocious.
450 How *do* you spell that odd word, anyways?
451 (Someone ask Mary -- she'll know [or she'll
452 say, "How should I know?"].)"""
453
454 for w in (10, 20, 30, 40):
455 print("width: %d" % w)
456 print("\n".join(wrap_text(text, w)))
457 print()
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