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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 .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() | |