def _get_args_from_signature(function):
if getattr(function, ATTR_EXPECTS_NAMESPACE_OBJECT, False):
return
spec = get_arg_spec(function)
defaults = dict(
zip(*[reversed(x) for x in (spec.args, spec.defaults or [])]))
defaults.update(getattr(spec, 'kwonlydefaults', None) or {})
kwonly = getattr(spec, 'kwonlyargs', [])
if sys.version_info < (3, 0):
annotations = {}
else:
annotations = dict((k, v) for k, v in function.__annotations__.items()
if isinstance(v, str))
# define the list of conflicting option strings
# (short forms, i.e. single-character ones)
chars = [a[0] for a in spec.args + kwonly]
char_counts = dict((char, chars.count(char)) for char in set(chars))
conflicting_opts = tuple(char for char in char_counts
if 1 < char_counts[char])
for name in spec.args + kwonly:
flags = [] # name_or_flags
akwargs = {} # keyword arguments for add_argument()
if name in annotations:
# help message: func(a : "b") -> add_argument("a", help="b")
akwargs.update(help=annotations.get(name))
if name in defaults or name in kwonly:
if name in defaults:
akwargs.update(default=defaults.get(name))
else:
akwargs.update(required=True)
flags = ('-{0}'.format(name[0]), '--{0}'.format(name))
if name.startswith(conflicting_opts):
# remove short name
flags = flags[1:]
else:
# positional argument
flags = (name, )
# cmd(foo_bar) -> add_argument('foo-bar')
flags = tuple(x.replace('_', '-') for x in flags)
yield dict(option_strings=flags, **akwargs)
if spec.varargs:
# *args
yield dict(option_strings=[spec.varargs], nargs='*')
def _get_args_from_signature(function):
if getattr(function, ATTR_EXPECTS_NAMESPACE_OBJECT, False):
return
spec = get_arg_spec(function)
defaults = dict(zip(*[reversed(x) for x in (spec.args,
spec.defaults or [])]))
defaults.update(getattr(spec, 'kwonlydefaults', None) or {})
kwonly = getattr(spec, 'kwonlyargs', [])
if sys.version_info < (3,0):
annotations = {}
else:
annotations = dict((k,v) for k,v in function.__annotations__.items()
if isinstance(v, str))
# define the list of conflicting option strings
# (short forms, i.e. single-character ones)
chars = [a[0] for a in spec.args + kwonly]
char_counts = dict((char, chars.count(char)) for char in set(chars))
conflicting_opts = tuple(char for char in char_counts
if 1 < char_counts[char])
for name in spec.args + kwonly:
flags = [] # name_or_flags
akwargs = {} # keyword arguments for add_argument()
if name in annotations:
# help message: func(a : "b") -> add_argument("a", help="b")
akwargs.update(help=annotations.get(name))
if name in defaults or name in kwonly:
if name in defaults:
akwargs.update(default=defaults.get(name))
else:
akwargs.update(required=True)
flags = ('-{0}'.format(name[0]), '--{0}'.format(name))
if name.startswith(conflicting_opts):
# remove short name
flags = flags[1:]
else:
# positional argument
flags = (name,)
# cmd(foo_bar) -> add_argument('foo-bar')
flags = tuple(x.replace('_', '-') for x in flags)
yield dict(option_strings=flags, **akwargs)
if spec.varargs:
# *args
yield dict(option_strings=[spec.varargs], nargs='*')
def _call():
# Actually call the function
if getattr(function, ATTR_EXPECTS_NAMESPACE_OBJECT, False):
result = function(namespace_obj)
else:
# namespace -> dictionary
_flat_key = lambda key: key.replace('-', '_')
all_input = dict(
(_flat_key(k), v) for k, v in vars(namespace_obj).items())
# filter the namespace variables so that only those expected
# by the actual function will pass
spec = get_arg_spec(function)
positional = [all_input[k] for k in spec.args]
kwonly = getattr(spec, 'kwonlyargs', [])
keywords = dict((k, all_input[k]) for k in kwonly)
# *args
if spec.varargs:
positional += getattr(namespace_obj, spec.varargs)
# **kwargs
varkw = getattr(spec, 'varkw', getattr(spec, 'keywords', []))
if varkw:
not_kwargs = [DEST_FUNCTION] + spec.args + [spec.varargs
] + kwonly
for k in vars(namespace_obj):
if k.startswith('_') or k in not_kwargs:
continue
keywords[k] = getattr(namespace_obj, k)
result = function(*positional, **keywords)
# Yield the results
if isinstance(result, (GeneratorType, list, tuple)):
# yield each line ASAP, convert CommandError message to a line
for line in result:
yield line
else:
# yield non-empty non-iterable result as a single line
if result is not None:
yield result
def _call():
# Actually call the function
if getattr(function, ATTR_EXPECTS_NAMESPACE_OBJECT, False):
result = function(namespace_obj)
else:
# namespace -> dictionary
_flat_key = lambda key: key.replace('-', '_')
all_input = dict((_flat_key(k), v)
for k,v in vars(namespace_obj).items())
# filter the namespace variables so that only those expected
# by the actual function will pass
spec = get_arg_spec(function)
positional = [all_input[k] for k in spec.args]
kwonly = getattr(spec, 'kwonlyargs', [])
keywords = dict((k, all_input[k]) for k in kwonly)
# *args
if spec.varargs:
positional += getattr(namespace_obj, spec.varargs)
# **kwargs
varkw = getattr(spec, 'varkw', getattr(spec, 'keywords', []))
if varkw:
not_kwargs = [DEST_FUNCTION] + spec.args + [spec.varargs] + kwonly
for k in vars(namespace_obj):
if k.startswith('_') or k in not_kwargs:
continue
keywords[k] = getattr(namespace_obj, k)
result = function(*positional, **keywords)
# Yield the results
if isinstance(result, (GeneratorType, list, tuple)):
# yield each line ASAP, convert CommandError message to a line
for line in result:
yield line
else:
# yield non-empty non-iterable result as a single line
if result is not None:
yield result
def set_default_command(parser, function):
"""
Sets default command (i.e. a function) for given parser.
If `parser.description` is empty and the function has a docstring,
it is used as the description.
.. note::
An attempt to set default command to a parser which already has
subparsers (e.g. added with :func:`~argh.assembling.add_commands`)
results in a `AssemblingError`.
.. note::
If there are both explicitly declared arguments (e.g. via
:func:`~argh.decorators.arg`) and ones inferred from the function
signature (e.g. via :func:`~argh.decorators.command`), declared ones
will be merged into inferred ones. If an argument does not conform
function signature, `AssemblingError` is raised.
.. note::
If the parser was created with ``add_help=True`` (which is by default),
option name ``-h`` is silently removed from any argument.
"""
if parser._subparsers:
_require_support_for_default_command_with_subparsers()
spec = get_arg_spec(function)
declared_args = getattr(function, ATTR_ARGS, [])
inferred_args = list(_get_args_from_signature(function))
if inferred_args and declared_args:
# We've got a mixture of declared and inferred arguments
# a mapping of "dest" strings to argument declarations.
#
# * a "dest" string is a normalized form of argument name, i.e.:
#
# '-f', '--foo' → 'foo'
# 'foo-bar' → 'foo_bar'
#
# * argument declaration is a dictionary representing an argument;
# it is obtained either from _get_args_from_signature() or from
# an @arg decorator (as is).
#
dests = OrderedDict()
for argspec in inferred_args:
dest = _get_parser_param_kwargs(parser, argspec)['dest']
dests[dest] = argspec
for declared_kw in declared_args:
# an argument is declared via decorator
dest = _get_dest(parser, declared_kw)
if dest in dests:
# the argument is already known from function signature
#
# now make sure that this declared arg conforms to the function
# signature and therefore only refines an inferred arg:
#
# @arg('my-foo') maps to func(my_foo)
# @arg('--my-bar') maps to func(my_bar=...)
# either both arguments are positional or both are optional
decl_positional = _is_positional(declared_kw['option_strings'])
infr_positional = _is_positional(dests[dest]['option_strings'])
if decl_positional != infr_positional:
kinds = {True: 'positional', False: 'optional'}
raise AssemblingError(
'{func}: argument "{dest}" declared as {kind_i} '
'(in function signature) and {kind_d} (via decorator)'.
format(
func=function.__name__,
dest=dest,
kind_i=kinds[infr_positional],
kind_d=kinds[decl_positional],
))
# merge explicit argument declaration into the inferred one
# (e.g. `help=...`)
dests[dest].update(**declared_kw)
else:
# the argument is not in function signature
varkw = getattr(spec, 'varkw', getattr(spec, 'keywords', []))
if varkw:
# function accepts **kwargs; the argument goes into it
dests[dest] = declared_kw
else:
# there's no way we can map the argument declaration
# to function signature
xs = (dests[x]['option_strings'] for x in dests)
raise AssemblingError(
'{func}: argument {flags} does not fit '
'function signature: {sig}'.format(
flags=', '.join(declared_kw['option_strings']),
func=function.__name__,
sig=', '.join('/'.join(x) for x in xs)))
# pack the modified data back into a list
inferred_args = dests.values()
command_args = inferred_args or declared_args
# add types, actions, etc. (e.g. default=3 implies type=int)
command_args = [_guess(x) for x in command_args]
for draft in command_args:
draft = draft.copy()
if 'help' not in draft:
draft.update(help=DEFAULT_ARGUMENT_TEMPLATE)
dest_or_opt_strings = draft.pop('option_strings')
if parser.add_help and '-h' in dest_or_opt_strings:
dest_or_opt_strings = [x for x in dest_or_opt_strings if x != '-h']
completer = draft.pop('completer', None)
try:
action = parser.add_argument(*dest_or_opt_strings, **draft)
if COMPLETION_ENABLED and completer:
action.completer = completer
except Exception as e:
raise type(e)('{func}: cannot add arg {args}: {msg}'.format(
args='/'.join(dest_or_opt_strings),
func=function.__name__,
msg=e))
if function.__doc__ and not parser.description:
parser.description = function.__doc__
parser.set_defaults(**{
DEST_FUNCTION: function,
})
def set_default_command(parser, function):
"""
Sets default command (i.e. a function) for given parser.
If `parser.description` is empty and the function has a docstring,
it is used as the description.
.. note::
An attempt to set default command to a parser which already has
subparsers (e.g. added with :func:`~argh.assembling.add_commands`)
results in a `AssemblingError`.
.. note::
If there are both explicitly declared arguments (e.g. via
:func:`~argh.decorators.arg`) and ones inferred from the function
signature (e.g. via :func:`~argh.decorators.command`), declared ones
will be merged into inferred ones. If an argument does not conform
function signature, `AssemblingError` is raised.
.. note::
If the parser was created with ``add_help=True`` (which is by default),
option name ``-h`` is silently removed from any argument.
"""
if parser._subparsers:
_require_support_for_default_command_with_subparsers()
spec = get_arg_spec(function)
declared_args = getattr(function, ATTR_ARGS, [])
inferred_args = list(_get_args_from_signature(function))
if inferred_args and declared_args:
# We've got a mixture of declared and inferred arguments
# a mapping of "dest" strings to argument declarations.
#
# * a "dest" string is a normalized form of argument name, i.e.:
#
# '-f', '--foo' → 'foo'
# 'foo-bar' → 'foo_bar'
#
# * argument declaration is a dictionary representing an argument;
# it is obtained either from _get_args_from_signature() or from
# an @arg decorator (as is).
#
dests = OrderedDict()
for argspec in inferred_args:
dest = _get_parser_param_kwargs(parser, argspec)['dest']
dests[dest] = argspec
for declared_kw in declared_args:
# an argument is declared via decorator
dest = _get_dest(parser, declared_kw)
if dest in dests:
# the argument is already known from function signature
#
# now make sure that this declared arg conforms to the function
# signature and therefore only refines an inferred arg:
#
# @arg('my-foo') maps to func(my_foo)
# @arg('--my-bar') maps to func(my_bar=...)
# either both arguments are positional or both are optional
decl_positional = _is_positional(declared_kw['option_strings'])
infr_positional = _is_positional(dests[dest]['option_strings'])
if decl_positional != infr_positional:
kinds = {True: 'positional', False: 'optional'}
raise AssemblingError(
'{func}: argument "{dest}" declared as {kind_i} '
'(in function signature) and {kind_d} (via decorator)'
.format(
func=function.__name__,
dest=dest,
kind_i=kinds[infr_positional],
kind_d=kinds[decl_positional],
))
# merge explicit argument declaration into the inferred one
# (e.g. `help=...`)
dests[dest].update(**declared_kw)
else:
# the argument is not in function signature
varkw = getattr(spec, 'varkw', getattr(spec, 'keywords', []))
if varkw:
# function accepts **kwargs; the argument goes into it
dests[dest] = declared_kw
else:
# there's no way we can map the argument declaration
# to function signature
xs = (dests[x]['option_strings'] for x in dests)
raise AssemblingError(
'{func}: argument {flags} does not fit '
'function signature: {sig}'.format(
flags=', '.join(declared_kw['option_strings']),
func=function.__name__,
sig=', '.join('/'.join(x) for x in xs)))
# pack the modified data back into a list
inferred_args = dests.values()
command_args = inferred_args or declared_args
# add types, actions, etc. (e.g. default=3 implies type=int)
command_args = [_guess(x) for x in command_args]
for draft in command_args:
draft = draft.copy()
if 'help' not in draft:
draft.update(help=DEFAULT_ARGUMENT_TEMPLATE)
dest_or_opt_strings = draft.pop('option_strings')
if parser.add_help and '-h' in dest_or_opt_strings:
dest_or_opt_strings = [x for x in dest_or_opt_strings if x != '-h']
completer = draft.pop('completer', None)
try:
action = parser.add_argument(*dest_or_opt_strings, **draft)
if COMPLETION_ENABLED and completer:
action.completer = completer
except Exception as e:
raise type(e)('{func}: cannot add arg {args}: {msg}'.format(
args='/'.join(dest_or_opt_strings), func=function.__name__, msg=e))
if function.__doc__ and not parser.description:
parser.description = function.__doc__
parser.set_defaults(**{
DEST_FUNCTION: function,
})
