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- """distutils.fancy_getopt
- Wrapper around the standard getopt module that provides the following
- additional features:
- * short and long options are tied together
- * options have help strings, so fancy_getopt could potentially
- create a complete usage summary
- * options set attributes of a passed-in object
- """
- import sys
- import string
- import re
- import getopt
- from distutils.errors import DistutilsGetoptError, DistutilsArgError
- # Much like command_re in distutils.core, this is close to but not quite
- # the same as a Python NAME -- except, in the spirit of most GNU
- # utilities, we use '-' in place of '_'. (The spirit of LISP lives on!)
- # The similarities to NAME are again not a coincidence...
- longopt_pat = r'[a-zA-Z](?:[a-zA-Z0-9-]*)'
- longopt_re = re.compile(r'^%s$' % longopt_pat)
- # For recognizing "negative alias" options, eg. "quiet=!verbose"
- neg_alias_re = re.compile("^({})=!({})$".format(longopt_pat, longopt_pat))
- # This is used to translate long options to legitimate Python identifiers
- # (for use as attributes of some object).
- longopt_xlate = str.maketrans('-', '_')
- class FancyGetopt:
- """Wrapper around the standard 'getopt()' module that provides some
- handy extra functionality:
- * short and long options are tied together
- * options have help strings, and help text can be assembled
- from them
- * options set attributes of a passed-in object
- * boolean options can have "negative aliases" -- eg. if
- --quiet is the "negative alias" of --verbose, then "--quiet"
- on the command line sets 'verbose' to false
- """
- def __init__(self, option_table=None):
- # The option table is (currently) a list of tuples. The
- # tuples may have 3 or four values:
- # (long_option, short_option, help_string [, repeatable])
- # if an option takes an argument, its long_option should have '='
- # appended; short_option should just be a single character, no ':'
- # in any case. If a long_option doesn't have a corresponding
- # short_option, short_option should be None. All option tuples
- # must have long options.
- self.option_table = option_table
- # 'option_index' maps long option names to entries in the option
- # table (ie. those 3-tuples).
- self.option_index = {}
- if self.option_table:
- self._build_index()
- # 'alias' records (duh) alias options; {'foo': 'bar'} means
- # --foo is an alias for --bar
- self.alias = {}
- # 'negative_alias' keeps track of options that are the boolean
- # opposite of some other option
- self.negative_alias = {}
- # These keep track of the information in the option table. We
- # don't actually populate these structures until we're ready to
- # parse the command-line, since the 'option_table' passed in here
- # isn't necessarily the final word.
- self.short_opts = []
- self.long_opts = []
- self.short2long = {}
- self.attr_name = {}
- self.takes_arg = {}
- # And 'option_order' is filled up in 'getopt()'; it records the
- # original order of options (and their values) on the command-line,
- # but expands short options, converts aliases, etc.
- self.option_order = []
- def _build_index(self):
- self.option_index.clear()
- for option in self.option_table:
- self.option_index[option[0]] = option
- def set_option_table(self, option_table):
- self.option_table = option_table
- self._build_index()
- def add_option(self, long_option, short_option=None, help_string=None):
- if long_option in self.option_index:
- raise DistutilsGetoptError(
- "option conflict: already an option '%s'" % long_option
- )
- else:
- option = (long_option, short_option, help_string)
- self.option_table.append(option)
- self.option_index[long_option] = option
- def has_option(self, long_option):
- """Return true if the option table for this parser has an
- option with long name 'long_option'."""
- return long_option in self.option_index
- def get_attr_name(self, long_option):
- """Translate long option name 'long_option' to the form it
- has as an attribute of some object: ie., translate hyphens
- to underscores."""
- return long_option.translate(longopt_xlate)
- def _check_alias_dict(self, aliases, what):
- assert isinstance(aliases, dict)
- for (alias, opt) in aliases.items():
- if alias not in self.option_index:
- raise DistutilsGetoptError(
- ("invalid %s '%s': " "option '%s' not defined")
- % (what, alias, alias)
- )
- if opt not in self.option_index:
- raise DistutilsGetoptError(
- ("invalid %s '%s': " "aliased option '%s' not defined")
- % (what, alias, opt)
- )
- def set_aliases(self, alias):
- """Set the aliases for this option parser."""
- self._check_alias_dict(alias, "alias")
- self.alias = alias
- def set_negative_aliases(self, negative_alias):
- """Set the negative aliases for this option parser.
- 'negative_alias' should be a dictionary mapping option names to
- option names, both the key and value must already be defined
- in the option table."""
- self._check_alias_dict(negative_alias, "negative alias")
- self.negative_alias = negative_alias
- def _grok_option_table(self): # noqa: C901
- """Populate the various data structures that keep tabs on the
- option table. Called by 'getopt()' before it can do anything
- worthwhile.
- """
- self.long_opts = []
- self.short_opts = []
- self.short2long.clear()
- self.repeat = {}
- for option in self.option_table:
- if len(option) == 3:
- long, short, help = option
- repeat = 0
- elif len(option) == 4:
- long, short, help, repeat = option
- else:
- # the option table is part of the code, so simply
- # assert that it is correct
- raise ValueError("invalid option tuple: {!r}".format(option))
- # Type- and value-check the option names
- if not isinstance(long, str) or len(long) < 2:
- raise DistutilsGetoptError(
- ("invalid long option '%s': " "must be a string of length >= 2")
- % long
- )
- if not ((short is None) or (isinstance(short, str) and len(short) == 1)):
- raise DistutilsGetoptError(
- "invalid short option '%s': "
- "must a single character or None" % short
- )
- self.repeat[long] = repeat
- self.long_opts.append(long)
- if long[-1] == '=': # option takes an argument?
- if short:
- short = short + ':'
- long = long[0:-1]
- self.takes_arg[long] = 1
- else:
- # Is option is a "negative alias" for some other option (eg.
- # "quiet" == "!verbose")?
- alias_to = self.negative_alias.get(long)
- if alias_to is not None:
- if self.takes_arg[alias_to]:
- raise DistutilsGetoptError(
- "invalid negative alias '%s': "
- "aliased option '%s' takes a value" % (long, alias_to)
- )
- self.long_opts[-1] = long # XXX redundant?!
- self.takes_arg[long] = 0
- # If this is an alias option, make sure its "takes arg" flag is
- # the same as the option it's aliased to.
- alias_to = self.alias.get(long)
- if alias_to is not None:
- if self.takes_arg[long] != self.takes_arg[alias_to]:
- raise DistutilsGetoptError(
- "invalid alias '%s': inconsistent with "
- "aliased option '%s' (one of them takes a value, "
- "the other doesn't" % (long, alias_to)
- )
- # Now enforce some bondage on the long option name, so we can
- # later translate it to an attribute name on some object. Have
- # to do this a bit late to make sure we've removed any trailing
- # '='.
- if not longopt_re.match(long):
- raise DistutilsGetoptError(
- "invalid long option name '%s' "
- "(must be letters, numbers, hyphens only" % long
- )
- self.attr_name[long] = self.get_attr_name(long)
- if short:
- self.short_opts.append(short)
- self.short2long[short[0]] = long
- def getopt(self, args=None, object=None): # noqa: C901
- """Parse command-line options in args. Store as attributes on object.
- If 'args' is None or not supplied, uses 'sys.argv[1:]'. If
- 'object' is None or not supplied, creates a new OptionDummy
- object, stores option values there, and returns a tuple (args,
- object). If 'object' is supplied, it is modified in place and
- 'getopt()' just returns 'args'; in both cases, the returned
- 'args' is a modified copy of the passed-in 'args' list, which
- is left untouched.
- """
- if args is None:
- args = sys.argv[1:]
- if object is None:
- object = OptionDummy()
- created_object = True
- else:
- created_object = False
- self._grok_option_table()
- short_opts = ' '.join(self.short_opts)
- try:
- opts, args = getopt.getopt(args, short_opts, self.long_opts)
- except getopt.error as msg:
- raise DistutilsArgError(msg)
- for opt, val in opts:
- if len(opt) == 2 and opt[0] == '-': # it's a short option
- opt = self.short2long[opt[1]]
- else:
- assert len(opt) > 2 and opt[:2] == '--'
- opt = opt[2:]
- alias = self.alias.get(opt)
- if alias:
- opt = alias
- if not self.takes_arg[opt]: # boolean option?
- assert val == '', "boolean option can't have value"
- alias = self.negative_alias.get(opt)
- if alias:
- opt = alias
- val = 0
- else:
- val = 1
- attr = self.attr_name[opt]
- # The only repeating option at the moment is 'verbose'.
- # It has a negative option -q quiet, which should set verbose = 0.
- if val and self.repeat.get(attr) is not None:
- val = getattr(object, attr, 0) + 1
- setattr(object, attr, val)
- self.option_order.append((opt, val))
- # for opts
- if created_object:
- return args, object
- else:
- return args
- def get_option_order(self):
- """Returns the list of (option, value) tuples processed by the
- previous run of 'getopt()'. Raises RuntimeError if
- 'getopt()' hasn't been called yet.
- """
- if self.option_order is None:
- raise RuntimeError("'getopt()' hasn't been called yet")
- else:
- return self.option_order
- def generate_help(self, header=None): # noqa: C901
- """Generate help text (a list of strings, one per suggested line of
- output) from the option table for this FancyGetopt object.
- """
- # Blithely assume the option table is good: probably wouldn't call
- # 'generate_help()' unless you've already called 'getopt()'.
- # First pass: determine maximum length of long option names
- max_opt = 0
- for option in self.option_table:
- long = option[0]
- short = option[1]
- ell = len(long)
- if long[-1] == '=':
- ell = ell - 1
- if short is not None:
- ell = ell + 5 # " (-x)" where short == 'x'
- if ell > max_opt:
- max_opt = ell
- opt_width = max_opt + 2 + 2 + 2 # room for indent + dashes + gutter
- # Typical help block looks like this:
- # --foo controls foonabulation
- # Help block for longest option looks like this:
- # --flimflam set the flim-flam level
- # and with wrapped text:
- # --flimflam set the flim-flam level (must be between
- # 0 and 100, except on Tuesdays)
- # Options with short names will have the short name shown (but
- # it doesn't contribute to max_opt):
- # --foo (-f) controls foonabulation
- # If adding the short option would make the left column too wide,
- # we push the explanation off to the next line
- # --flimflam (-l)
- # set the flim-flam level
- # Important parameters:
- # - 2 spaces before option block start lines
- # - 2 dashes for each long option name
- # - min. 2 spaces between option and explanation (gutter)
- # - 5 characters (incl. space) for short option name
- # Now generate lines of help text. (If 80 columns were good enough
- # for Jesus, then 78 columns are good enough for me!)
- line_width = 78
- text_width = line_width - opt_width
- big_indent = ' ' * opt_width
- if header:
- lines = [header]
- else:
- lines = ['Option summary:']
- for option in self.option_table:
- long, short, help = option[:3]
- text = wrap_text(help, text_width)
- if long[-1] == '=':
- long = long[0:-1]
- # Case 1: no short option at all (makes life easy)
- if short is None:
- if text:
- lines.append(" --%-*s %s" % (max_opt, long, text[0]))
- else:
- lines.append(" --%-*s " % (max_opt, long))
- # Case 2: we have a short option, so we have to include it
- # just after the long option
- else:
- opt_names = "{} (-{})".format(long, short)
- if text:
- lines.append(" --%-*s %s" % (max_opt, opt_names, text[0]))
- else:
- lines.append(" --%-*s" % opt_names)
- for ell in text[1:]:
- lines.append(big_indent + ell)
- return lines
- def print_help(self, header=None, file=None):
- if file is None:
- file = sys.stdout
- for line in self.generate_help(header):
- file.write(line + "\n")
- def fancy_getopt(options, negative_opt, object, args):
- parser = FancyGetopt(options)
- parser.set_negative_aliases(negative_opt)
- return parser.getopt(args, object)
- WS_TRANS = {ord(_wschar): ' ' for _wschar in string.whitespace}
- def wrap_text(text, width):
- """wrap_text(text : string, width : int) -> [string]
- Split 'text' into multiple lines of no more than 'width' characters
- each, and return the list of strings that results.
- """
- if text is None:
- return []
- if len(text) <= width:
- return [text]
- text = text.expandtabs()
- text = text.translate(WS_TRANS)
- chunks = re.split(r'( +|-+)', text)
- chunks = [ch for ch in chunks if ch] # ' - ' results in empty strings
- lines = []
- while chunks:
- cur_line = [] # list of chunks (to-be-joined)
- cur_len = 0 # length of current line
- while chunks:
- ell = len(chunks[0])
- if cur_len + ell <= width: # can squeeze (at least) this chunk in
- cur_line.append(chunks[0])
- del chunks[0]
- cur_len = cur_len + ell
- else: # this line is full
- # drop last chunk if all space
- if cur_line and cur_line[-1][0] == ' ':
- del cur_line[-1]
- break
- if chunks: # any chunks left to process?
- # if the current line is still empty, then we had a single
- # chunk that's too big too fit on a line -- so we break
- # down and break it up at the line width
- if cur_len == 0:
- cur_line.append(chunks[0][0:width])
- chunks[0] = chunks[0][width:]
- # all-whitespace chunks at the end of a line can be discarded
- # (and we know from the re.split above that if a chunk has
- # *any* whitespace, it is *all* whitespace)
- if chunks[0][0] == ' ':
- del chunks[0]
- # and store this line in the list-of-all-lines -- as a single
- # string, of course!
- lines.append(''.join(cur_line))
- return lines
- def translate_longopt(opt):
- """Convert a long option name to a valid Python identifier by
- changing "-" to "_".
- """
- return opt.translate(longopt_xlate)
- class OptionDummy:
- """Dummy class just used as a place to hold command-line option
- values as instance attributes."""
- def __init__(self, options=[]):
- """Create a new OptionDummy instance. The attributes listed in
- 'options' will be initialized to None."""
- for opt in options:
- setattr(self, opt, None)
- if __name__ == "__main__":
- text = """\
- Tra-la-la, supercalifragilisticexpialidocious.
- How *do* you spell that odd word, anyways?
- (Someone ask Mary -- she'll know [or she'll
- say, "How should I know?"].)"""
- for w in (10, 20, 30, 40):
- print("width: %d" % w)
- print("\n".join(wrap_text(text, w)))
- print()
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