"""Pythonic command-line interface parser that will make you smile.
* http://docopt.org
* Repository and issue-tracker: https://github.com/docopt/docopt
* Licensed under terms of MIT license (see LICENSE-MIT)
* Copyright (c) 2013 Vladimir Keleshev, vladimir@keleshev.com
"""
import sys
import re
__all__ = ['docopt']
__version__ = '0.6.2'
class DocoptLanguageError(Exception):
"""Error in construction of usage-message by developer."""
class DocoptExit(SystemExit):
"""Exit in case user invoked program with incorrect arguments."""
usage = ''
def __init__(self, message=''):
SystemExit.__init__(self, (message + '\n' + self.usage).strip())
class Pattern(object):
def __eq__(self, other):
return repr(self) == repr(other)
def __hash__(self):
return hash(repr(self))
def fix(self):
self.fix_identities()
self.fix_repeating_arguments()
return self
def fix_identities(self, uniq=None):
"""Make pattern-tree tips point to same object if they are equal."""
if not hasattr(self, 'children'):
return self
uniq = list(set(self.flat())) if uniq is None else uniq
for i, c in enumerate(self.children):
if not hasattr(c, 'children'):
assert c in uniq
self.children[i] = uniq[uniq.index(c)]
else:
c.fix_identities(uniq)
def fix_repeating_arguments(self):
"""Fix elements that should accumulate/increment values."""
either = [list(c.children) for c in self.either.children]
for case in either:
for e in [c for c in case if case.count(c) > 1]:
if type(e) is Argument or type(e) is Option and e.argcount:
if e.value is None:
e.value = []
elif type(e.value) is not list:
e.value = e.value.split()
if type(e) is Command or type(e) is Option and e.argcount == 0:
e.value = 0
return self
@property
def either(self):
"""Transform pattern into an equivalent, with only top-level Either."""
# Currently the pattern will not be equivalent, but more "narrow",
# although good enough to reason about list arguments.
ret = []
groups = [[self]]
while groups:
children = groups.pop(0)
types = [type(c) for c in children]
if Either in types:
either = [c for c in children if type(c) is Either][0]
children.pop(children.index(either))
for c in either.children:
groups.append([c] + children)
elif Required in types:
required = [c for c in children if type(c) is Required][0]
children.pop(children.index(required))
groups.append(list(required.children) + children)
elif Optional in types:
optional = [c for c in children if type(c) is Optional][0]
children.pop(children.index(optional))
groups.append(list(optional.children) + children)
elif AnyOptions in types:
optional = [c for c in children if type(c) is AnyOptions][0]
children.pop(children.index(optional))
groups.append(list(optional.children) + children)
elif OneOrMore in types:
oneormore = [c for c in children if type(c) is OneOrMore][0]
children.pop(children.index(oneormore))
groups.append(list(oneormore.children) * 2 + children)
else:
ret.append(children)
return Either(*[Required(*e) for e in ret])
class ChildPattern(Pattern):
def __init__(self, name, value=None):
self.name = name
self.value = value
def __repr__(self):
return '%s(%r, %r)' % (self.__class__.__name__, self.name, self.value)
def flat(self, *types):
return [self] if not types or type(self) in types else []
def match(self, left, collected=None):
collected = [] if collected is None else collected
pos, match = self.single_match(left)
if match is None:
return False, left, collected
left_ = left[:pos] + left[pos + 1:]
same_name = [a for a in collected if a.name == self.name]
if type(self.value) in (int, list):
if type(self.value) is int:
increment = 1
else:
increment = ([match.value] if type(match.value) is str
else match.value)
if not same_name:
match.value = increment
return True, left_, collected + [match]
same_name[0].value += increment
return True, left_, collected
return True, left_, collected + [match]
class ParentPattern(Pattern):
def __init__(self, *children):
self.children = list(children)
def __repr__(self):
return '%s(%s)' % (self.__class__.__name__,
', '.join(repr(a) for a in self.children))
def flat(self, *types):
if type(self) in types:
return [self]
return sum([c.flat(*types) for c in self.children], [])
class Argument(ChildPattern):
def single_match(self, left):
for n, p in enumerate(left):
if type(p) is Argument:
return n, Argument(self.name, p.value)
return None, None
@classmethod
def parse(class_, source):
name = re.findall('(<\S*?>)', source)[0]
value = re.findall('\[default: (.*)\]', source, flags=re.I)
return class_(name, value[0] if value else None)
class Command(Argument):
def __init__(self, name, value=False):
self.name = name
self.value = value
def single_match(self, left):
for n, p in enumerate(left):
if type(p) is Argument:
if p.value == self.name:
return n, Command(self.name, True)
else:
break
return None, None
class Option(ChildPattern):
def __init__(self, short=None, long=None, argcount=0, value=False):
assert argcount in (0, 1)
self.short, self.long = short, long
self.argcount, self.value = argcount, value
self.value = None if value is False and argcount else value
@classmethod
def parse(class_, option_description):
short, long, argcount, value = None, None, 0, False
options, _, description = option_description.strip().partition(' ')
options = options.replace(',', ' ').replace('=', ' ')
for s in options.split():
if s.startswith('--'):
long = s
elif s.startswith('-'):
short = s
else:
argcount = 1
if argcount:
matched = re.findall('\[default: (.*)\]', description, flags=re.I)
value = matched[0] if matched else None
return class_(short, long, argcount, value)
def single_match(self, left):
for n, p in enumerate(left):
if self.name == p.name:
return n, p
return None, None
@property
def name(self):
return self.long or self.short
def __repr__(self):
return 'Option(%r, %r, %r, %r)' % (self.short, self.long,
self.argcount, self.value)
class Required(ParentPattern):
def match(self, left, collected=None):
collected = [] if collected is None else collected
l = left
c = collected
for p in self.children:
matched, l, c = p.match(l, c)
if not matched:
return False, left, collected
return True, l, c
class Optional(ParentPattern):
def match(self, left, collected=None):
collected = [] if collected is None else collected
for p in self.children:
m, left, collected = p.match(left, collected)
return True, left, collected
class AnyOptions(Optional):
"""Marker/placeholder for [options] shortcut."""
class OneOrMore(ParentPattern):
def match(self, left, collected=None):
assert len(self.children) == 1
collected = [] if collected is None else collected
l = left
c = collected
l_ = None
matched = True
times = 0
while matched:
# could it be that something didn't match but changed l or c?
matched, l, c = self.children[0].match(l, c)
times += 1 if matched else 0
if l_ == l:
break
l_ = l
if times >= 1:
return True, l, c
return False, left, collected
class Either(ParentPattern):
def match(self, left, collected=None):
collected = [] if collected is None else collected
outcomes = []
for p in self.children:
matched, _, _ = outcome = p.match(left, collected)
if matched:
outcomes.append(outcome)
if outcomes:
return min(outcomes, key=lambda outcome: len(outcome[1]))
return False, left, collected
class TokenStream(list):
def __init__(self, source, error):
self += source.split() if hasattr(source, 'split') else source
self.error = error
def move(self):
return self.pop(0) if len(self) else None
def current(self):
return self[0] if len(self) else None
def parse_long(tokens, options):
"""long ::= '--' chars [ ( ' ' | '=' ) chars ] ;"""
long, eq, value = tokens.move().partition('=')
assert long.startswith('--')
value = None if eq == value == '' else value
similar = [o for o in options if o.long == long]
if tokens.error is DocoptExit and similar == []: # if no exact match
similar = [o for o in options if o.long and o.long.startswith(long)]
if len(similar) > 1: # might be simply specified ambiguously 2+ times?
raise tokens.error('%s is not a unique prefix: %s?' %
(long, ', '.join(o.long for o in similar)))
elif len(similar) < 1:
argcount = 1 if eq == '=' else 0
o = Option(None, long, argcount)
options.append(o)
if tokens.error is DocoptExit:
o = Option(None, long, argcount, value if argcount else True)
else:
o = Option(similar[0].short, similar[0].long,
similar[0].argcount, similar[0].value)
if o.argcount == 0:
if value is not None:
raise tokens.error('%s must not have an argument' % o.long)
else:
if value is None:
if tokens.current() is None:
raise tokens.error('%s requires argument' % o.long)
value = tokens.move()
if tokens.error is DocoptExit:
o.value = value if value is not None else True
return [o]
def parse_shorts(tokens, options):
"""shorts ::= '-' ( chars )* [ [ ' ' ] chars ] ;"""
token = tokens.move()
assert token.startswith('-') and not token.startswith('--')
left = token.lstrip('-')
parsed = []
while left != '':
short, left = '-' + left[0], left[1:]
similar = [o for o in options if o.short == short]
if len(similar) > 1:
raise tokens.error('%s is specified ambiguously %d times' %
(short, len(similar)))
elif len(similar) < 1:
o = Option(short, None, 0)
options.append(o)
if tokens.error is DocoptExit:
o = Option(short, None, 0, True)
else: # why copying is necessary here?
o = Option(short, similar[0].long,
similar[0].argcount, similar[0].value)
value = None
if o.argcount != 0:
if left == '':
if tokens.current() is None:
raise tokens.error('%s requires argument' % short)
value = tokens.move()
else:
value = left
left = ''
if tokens.error is DocoptExit:
o.value = value if value is not None else True
parsed.append(o)
return parsed
def parse_pattern(source, options):
tokens = TokenStream(re.sub(r'([\[\]\(\)\|]|\.\.\.)', r' \1 ', source),
DocoptLanguageError)
result = parse_expr(tokens, options)
if tokens.current() is not None:
raise tokens.error('unexpected ending: %r' % ' '.join(tokens))
return Required(*result)
def parse_expr(tokens, options):
"""expr ::= seq ( '|' seq )* ;"""
seq = parse_seq(tokens, options)
if tokens.current() != '|':
return seq
result = [Required(*seq)] if len(seq) > 1 else seq
while tokens.current() == '|':
tokens.move()
seq = parse_seq(tokens, options)
result += [Required(*seq)] if len(seq) > 1 else seq
return [Either(*result)] if len(result) > 1 else result
def parse_seq(tokens, options):
"""seq ::= ( atom [ '...' ] )* ;"""
result = []
while tokens.current() not in [None, ']', ')', '|']:
atom = parse_atom(tokens, options)
if tokens.current() == '...':
atom = [OneOrMore(*atom)]
tokens.move()
result += atom
return result
def parse_atom(tokens, options):
"""atom ::= '(' expr ')' | '[' expr ']' | 'options'
| long | shorts | argument | command ;
"""
token = tokens.current()
result = []
if token in '([':
tokens.move()
matching, pattern = {'(': [')', Required], '[': [']', Optional]}[token]
result = pattern(*parse_expr(tokens, options))
if tokens.move() != matching:
raise tokens.error("unmatched '%s'" % token)
return [result]
elif token == 'options':
tokens.move()
return [AnyOptions()]
elif token.startswith('--') and token != '--':
return parse_long(tokens, options)
elif token.startswith('-') and token not in ('-', '--'):
return parse_shorts(tokens, options)
elif token.startswith('<') and token.endswith('>') or token.isupper():
return [Argument(tokens.move())]
else:
return [Command(tokens.move())]
def parse_argv(tokens, options, options_first=False):
"""Parse command-line argument vector.
If options_first:
argv ::= [ long | shorts ]* [ argument ]* [ '--' [ argument ]* ] ;
else:
argv ::= [ long | shorts | argument ]* [ '--' [ argument ]* ] ;
"""
parsed = []
while tokens.current() is not None:
if tokens.current() == '--':
return parsed + [Argument(None, v) for v in tokens]
elif tokens.current().startswith('--'):
parsed += parse_long(tokens, options)
elif tokens.current().startswith('-') and tokens.current() != '-':
parsed += parse_shorts(tokens, options)
elif options_first:
return parsed + [Argument(None, v) for v in tokens]
else:
parsed.append(Argument(None, tokens.move()))
return parsed
def parse_defaults(doc):
# in python < 2.7 you can't pass flags=re.MULTILINE
split = re.split('\n *(<\S+?>|-\S+?)', doc)[1:]
split = [s1 + s2 for s1, s2 in zip(split[::2], split[1::2])]
options = [Option.parse(s) for s in split if s.startswith('-')]
#arguments = [Argument.parse(s) for s in split if s.startswith('<')]
#return options, arguments
return options
def printable_usage(doc):
# in python < 2.7 you can't pass flags=re.IGNORECASE
usage_split = re.split(r'([Uu][Ss][Aa][Gg][Ee]:)', doc)
if len(usage_split) < 3:
raise DocoptLanguageError('"usage:" (case-insensitive) not found.')
if len(usage_split) > 3:
raise DocoptLanguageError('More than one "usage:" (case-insensitive).')
return re.split(r'\n\s*\n', ''.join(usage_split[1:]))[0].strip()
def formal_usage(printable_usage):
pu = printable_usage.split()[1:] # split and drop "usage:"
return '( ' + ' '.join(') | (' if s == pu[0] else s for s in pu[1:]) + ' )'
def extras(help, version, options, doc):
if help and any((o.name in ('-h', '--help')) and o.value for o in options):
print(doc.strip("\n"))
sys.exit()
if version and any(o.name == '--version' and o.value for o in options):
print(version)
sys.exit()
class Dict(dict):
def __repr__(self):
return '{%s}' % ',\n '.join('%r: %r' % i for i in sorted(self.items()))
def docopt(doc, argv=None, help=True, version=None, options_first=False):
"""Parse `argv` based on command-line interface described in `doc`.
`docopt` creates your command-line interface based on its
description that you pass as `doc`. Such description can contain
--options, <positional-argument>, commands, which could be
[optional], (required), (mutually | exclusive) or repeated...
Parameters
----------
doc : str
Description of your command-line interface.
argv : list of str, optional
Argument vector to be parsed. sys.argv[1:] is used if not
provided.
help : bool (default: True)
Set to False to disable automatic help on -h or --help
options.
version : any object
If passed, the object will be printed if --version is in
`argv`.
options_first : bool (default: False)
Set to True to require options preceed positional arguments,
i.e. to forbid options and positional arguments intermix.
Returns
-------
args : dict
A dictionary, where keys are names of command-line elements
such as e.g. "--verbose" and "<path>", and values are the
parsed values of those elements.
Example
-------
>>> from docopt import docopt
>>> doc = '''
Usage:
my_program tcp <host> <port> [--timeout=<seconds>]
my_program serial <port> [--baud=<n>] [--timeout=<seconds>]
my_program (-h | --help | --version)
Options:
-h, --help Show this screen and exit.
--baud=<n> Baudrate [default: 9600]
'''
>>> argv = ['tcp', '127.0.0.1', '80', '--timeout', '30']
>>> docopt(doc, argv)
{'--baud': '9600',
'--help': False,
'--timeout': '30',
'--version': False,
'<host>': '127.0.0.1',
'<port>': '80',
'serial': False,
'tcp': True}
See also
--------
* For video introduction see http://docopt.org
* Full documentation is available in README.rst as well as online
at https://github.com/docopt/docopt#readme
"""
if argv is None:
argv = sys.argv[1:]
DocoptExit.usage = printable_usage(doc)
options = parse_defaults(doc)
pattern = parse_pattern(formal_usage(DocoptExit.usage), options)
# [default] syntax for argument is disabled
#for a in pattern.flat(Argument):
# same_name = [d for d in arguments if d.name == a.name]
# if same_name:
# a.value = same_name[0].value
argv = parse_argv(TokenStream(argv, DocoptExit), list(options),
options_first)
pattern_options = set(pattern.flat(Option))
for ao in pattern.flat(AnyOptions):
doc_options = parse_defaults(doc)
ao.children = list(set(doc_options) - pattern_options)
#if any_options:
# ao.children += [Option(o.short, o.long, o.argcount)
# for o in argv if type(o) is Option]
extras(help, version, argv, doc)
matched, left, collected = pattern.fix().match(argv)
if matched and left == []: # better error message if left?
return Dict((a.name, a.value) for a in (pattern.flat() + collected))
raise DocoptExit()
