class ParserContext(object):
"""
Parsing context with knowledge of flags & their format.
Generally associated with the core program or a task.
When run through a parser, will also hold runtime values filled in by the
parser.
.. versionadded:: 1.0
"""
def __init__(self, name=None, aliases=(), args=()):
"""
Create a new ``ParserContext`` named ``name``, with ``aliases``.
``name`` is optional, and should be a string if given. It's used to
tell ParserContext objects apart, and for use in a Parser when
determining what chunk of input might belong to a given ParserContext.
``aliases`` is also optional and should be an iterable containing
strings. Parsing will honor any aliases when trying to "find" a given
context in its input.
May give one or more ``args``, which is a quick alternative to calling
``for arg in args: self.add_arg(arg)`` after initialization.
"""
self.args = Lexicon()
self.positional_args = []
self.flags = Lexicon()
self.inverse_flags = {} # No need for Lexicon here
self.name = name
self.aliases = aliases
for arg in args:
self.add_arg(arg)
def __repr__(self):
aliases = ""
if self.aliases:
aliases = " ({})".format(', '.join(self.aliases))
name = (" {!r}{}".format(self.name, aliases)) if self.name else ""
args = (": {!r}".format(self.args)) if self.args else ""
return "<parser/Context{}{}>".format(name, args)
def add_arg(self, *args, **kwargs):
"""
Adds given ``Argument`` (or constructor args for one) to this context.
The Argument in question is added to the following dict attributes:
* ``args``: "normal" access, i.e. the given names are directly exposed
as keys.
* ``flags``: "flaglike" access, i.e. the given names are translated
into CLI flags, e.g. ``"foo"`` is accessible via ``flags['--foo']``.
* ``inverse_flags``: similar to ``flags`` but containing only the
"inverse" versions of boolean flags which default to True. This
allows the parser to track e.g. ``--no-myflag`` and turn it into a
False value for the ``myflag`` Argument.
.. versionadded:: 1.0
"""
# Normalize
if len(args) == 1 and isinstance(args[0], Argument):
arg = args[0]
else:
arg = Argument(*args, **kwargs)
# Uniqueness constraint: no name collisions
for name in arg.names:
if name in self.args:
msg = "Tried to add an argument named {!r} but one already exists!" # noqa
raise ValueError(msg.format(name))
# First name used as "main" name for purposes of aliasing
main = arg.names[0] # NOT arg.name
self.args[main] = arg
# Note positionals in distinct, ordered list attribute
if arg.positional:
self.positional_args.append(arg)
# Add names & nicknames to flags, args
self.flags[to_flag(main)] = arg
for name in arg.nicknames:
self.args.alias(name, to=main)
self.flags.alias(to_flag(name), to=to_flag(main))
# Add attr_name to args, but not flags
if arg.attr_name:
self.args.alias(arg.attr_name, to=main)
# Add to inverse_flags if required
if arg.kind == bool and arg.default is True:
# Invert the 'main' flag name here, which will be a dashed version
# of the primary argument name if underscore-to-dash transformation
# occurred.
inverse_name = to_flag("no-{}".format(main))
self.inverse_flags[inverse_name] = to_flag(main)
@property
def missing_positional_args(self):
return [x for x in self.positional_args if x.value is None]
@property
def as_kwargs(self):
"""
This context's arguments' values keyed by their ``.name`` attribute.
Results in a dict suitable for use in Python contexts, where e.g. an
arg named ``foo-bar`` becomes accessible as ``foo_bar``.
.. versionadded:: 1.0
"""
ret = {}
for arg in self.args.values():
ret[arg.name] = arg.value
return ret
def names_for(self, flag):
# TODO: should probably be a method on Lexicon/AliasDict
return list(set([flag] + self.flags.aliases_of(flag)))
def help_for(self, flag):
"""
Return 2-tuple of ``(flag-spec, help-string)`` for given ``flag``.
.. versionadded:: 1.0
"""
# Obtain arg obj
if flag not in self.flags:
err = "{!r} is not a valid flag for this context! Valid flags are: {!r}" # noqa
raise ValueError(err.format(flag, self.flags.keys()))
arg = self.flags[flag]
# Determine expected value type, if any
value = {
str: 'STRING',
int: 'INT',
}.get(arg.kind)
# Format & go
full_names = []
for name in self.names_for(flag):
if value:
# Short flags are -f VAL, long are --foo=VAL
# When optional, also, -f [VAL] and --foo[=VAL]
if len(name.strip('-')) == 1:
value_ = ("[{}]".format(value)) if arg.optional else value
valuestr = " {}".format(value_)
else:
valuestr = "={}".format(value)
if arg.optional:
valuestr = "[{}]".format(valuestr)
else:
# no value => boolean
# check for inverse
if name in self.inverse_flags.values():
name = "--[no-]{}".format(name[2:])
valuestr = ""
# Tack together
full_names.append(name + valuestr)
namestr = ", ".join(sorted(full_names, key=len))
helpstr = arg.help or ""
return namestr, helpstr
def help_tuples(self):
"""
Return sorted iterable of help tuples for all member Arguments.
Sorts like so:
* General sort is alphanumerically
* Short flags win over long flags
* Arguments with *only* long flags and *no* short flags will come
first.
* When an Argument has multiple long or short flags, it will sort using
the most favorable (lowest alphabetically) candidate.
This will result in a help list like so::
--alpha, --zeta # 'alpha' wins
--beta
-a, --query # short flag wins
-b, --argh
-c
.. versionadded:: 1.0
"""
# TODO: argument/flag API must change :(
# having to call to_flag on 1st name of an Argument is just dumb.
# To pass in an Argument object to help_for may require moderate
# changes?
# Cast to list to ensure non-generator on Python 3.
return list(map(
lambda x: self.help_for(to_flag(x.name)),
sorted(self.flags.values(), key=flag_key)
))
def flag_names(self):
"""
Similar to `help_tuples` but returns flag names only, no helpstrs.
Specifically, all flag names, flattened, in rough order.
.. versionadded:: 1.0
"""
# Regular flag names
flags = sorted(self.flags.values(), key=flag_key)
names = [self.names_for(to_flag(x.name)) for x in flags]
# Inverse flag names sold separately
names.append(self.inverse_flags.keys())
return tuple(itertools.chain.from_iterable(names))
class Collection(object):
"""
A collection of executable tasks.
"""
def __init__(self, *args, **kwargs):
"""
Create a new task collection/namespace.
`.Collection` offers a set of methods for building a collection of
tasks from scratch, plus a convenient constructor wrapping said API.
In either case:
* the first positional argument may be a string, which (if given) is
used as the collection's default name when performing namespace
lookups;
* a ``loaded_from`` keyword argument may be given, which sets metadata
indicating the filesystem path the collection was loaded from. This
is used as a guide when loading per-project :ref:`configuration files
<config-hierarchy>`.
**The method approach**
May initialize with no arguments and use methods (e.g.
`.add_task`/`.add_collection`) to insert objects::
c = Collection()
c.add_task(some_task)
If an initial string argument is given, it is used as the default name
for this collection, should it be inserted into another collection as a
sub-namespace::
docs = Collection('docs')
docs.add_task(doc_task)
ns = Collection()
ns.add_task(top_level_task)
ns.add_collection(docs)
# Valid identifiers are now 'top_level_task' and 'docs.doc_task'
# (assuming the task objects were actually named the same as the
# variables we're using :))
For details, see the API docs for the rest of the class.
**The constructor approach**
All ``*args`` given to `.Collection` (besides the abovementioned
optional positional 'name' argument and ``loaded_from`` kwarg) are
expected to be `.Task` or `.Collection` instances which will be passed
to `.add_task`/`.add_collection` as appropriate. Module objects are
also valid (as they are for `.add_collection`). For example, the below
snippet results in the same two task identifiers as the one above::
ns = Collection(top_level_task, Collection('docs', doc_task))
If any ``**kwargs`` are given, the keywords are used as the initial
name arguments for the respective values::
ns = Collection(
top_level_task=some_other_task,
docs=Collection(doc_task)
)
That's exactly equivalent to::
docs = Collection(doc_task)
ns = Collection()
ns.add_task(some_other_task, 'top_level_task')
ns.add_collection(docs, 'docs')
See individual methods' API docs for details.
"""
# Initialize
self.tasks = Lexicon()
self.collections = Lexicon()
self.default = None
self.name = None
self._configuration = {}
# Name if applicable
args = list(args)
if args and isinstance(args[0], six.string_types):
self.name = args.pop(0)
# Specific kwargs if applicable
self.loaded_from = kwargs.pop('loaded_from', None)
# Dispatch args/kwargs
for arg in args:
self._add_object(arg)
# Dispatch kwargs
for name, obj in six.iteritems(kwargs):
self._add_object(obj, name)
def _add_object(self, obj, name=None):
if isinstance(obj, Task):
method = self.add_task
elif isinstance(obj, (Collection, types.ModuleType)):
method = self.add_collection
else:
raise TypeError("No idea how to insert {0!r}!".format(type(obj)))
return method(obj, name=name)
def __repr__(self):
return "<Collection {0!r}: {1}>".format(
self.name,
", ".join(sorted(self.tasks.keys())),
)
def __eq__(self, other):
return self.name == other.name and self.tasks == other.tasks
@classmethod
def from_module(self, module, name=None, config=None, loaded_from=None):
"""
Return a new `.Collection` created from ``module``.
Inspects ``module`` for any `.Task` instances and adds them to a new
`.Collection`, returning it. If any explicit namespace collections
exist (named ``ns`` or ``namespace``) a copy of that collection object
is preferentially loaded instead.
When the implicit/default collection is generated, it will be named
after the module's ``__name__`` attribute, or its last dotted section
if it's a submodule. (I.e. it should usually map to the actual ``.py``
filename.)
Explicitly given collections will only be given that module-derived
name if they don't already have a valid ``.name`` attribute.
:param str name:
A string, which if given will override any automatically derived
collection name (or name set on the module's root namespace, if it
has one.)
:param dict config:
Used to set config options on the newly created `.Collection`
before returning it (saving you a call to `.configure`.)
If the imported module had a root namespace object, ``config`` is
merged on top of it (i.e. overriding any conflicts.)
:param str loaded_from:
Identical to the same-named kwarg from the regular class
constructor - should be the path where the module was
found.
"""
module_name = module.__name__.split('.')[-1]
# See if the module provides a default NS to use in lieu of creating
# our own collection.
for candidate in ('ns', 'namespace'):
obj = getattr(module, candidate, None)
if obj and isinstance(obj, Collection):
# TODO: make this into Collection.clone() or similar
# Explicitly given name wins over root ns name which wins over
# actual module name.
ret = Collection(name or obj.name or module_name,
loaded_from=loaded_from)
ret.tasks = copy.deepcopy(obj.tasks)
ret.collections = copy.deepcopy(obj.collections)
ret.default = copy.deepcopy(obj.default)
# Explicitly given config wins over root ns config
obj_config = copy_dict(obj._configuration)
if config:
merge_dicts(obj_config, config)
ret._configuration = obj_config
return ret
# Failing that, make our own collection from the module's tasks.
tasks = filter(
lambda x: isinstance(x, Task),
vars(module).values()
)
# Again, explicit name wins over implicit one from module path
collection = Collection(name or module_name, loaded_from=loaded_from)
for task in tasks:
collection.add_task(task)
if config:
collection.configure(config)
return collection
def add_task(self, task, name=None, default=None):
"""
Add `.Task` ``task`` to this collection.
:param task: The `.Task` object to add to this collection.
:param name:
Optional string name to bind to (overrides the task's own
self-defined ``name`` attribute and/or any Python identifier (i.e.
``.func_name``.)
:param default: Whether this task should be the collection default.
"""
if name is None:
if task.name:
name = task.name
elif hasattr(task.body, 'func_name'):
name = task.body.func_name
elif hasattr(task.body, '__name__'):
name = task.__name__
else:
raise ValueError("Could not obtain a name for this task!")
if name in self.collections:
raise ValueError("Name conflict: this collection has a sub-collection named {0!r} already".format(name)) # noqa
self.tasks[name] = task
for alias in task.aliases:
self.tasks.alias(alias, to=name)
if default is True or (default is None and task.is_default):
if self.default:
msg = "'{0}' cannot be the default because '{1}' already is!"
raise ValueError(msg.format(name, self.default))
self.default = name
def add_collection(self, coll, name=None):
"""
Add `.Collection` ``coll`` as a sub-collection of this one.
:param coll: The `.Collection` to add.
:param str name:
The name to attach the collection as. Defaults to the collection's
own internal name.
"""
# Handle module-as-collection
if isinstance(coll, types.ModuleType):
coll = Collection.from_module(coll)
# Ensure we have a name, or die trying
name = name or coll.name
if not name:
raise ValueError("Non-root collections must have a name!")
# Test for conflict
if name in self.tasks:
raise ValueError("Name conflict: this collection has a task named {0!r} already".format(name)) # noqa
# Insert
self.collections[name] = coll
def split_path(self, path):
"""
Obtain first collection + remainder, of a task path.
E.g. for ``"subcollection.taskname"``, return ``("subcollection",
"taskname")``; for ``"subcollection.nested.taskname"`` return
``("subcollection", "nested.taskname")``, etc.
An empty path becomes simply ``('', '')``.
"""
parts = path.split('.')
coll = parts.pop(0)
rest = '.'.join(parts)
return coll, rest
def __getitem__(self, name=None):
"""
Returns task named ``name``. Honors aliases and subcollections.
If this collection has a default task, it is returned when ``name`` is
empty or ``None``. If empty input is given and no task has been
selected as the default, ValueError will be raised.
Tasks within subcollections should be given in dotted form, e.g.
'foo.bar'. Subcollection default tasks will be returned on the
subcollection's name.
"""
return self.task_with_config(name)[0]
def _task_with_merged_config(self, coll, rest, ours):
task, config = self.collections[coll].task_with_config(rest)
return task, dict(config, **ours)
def task_with_config(self, name):
"""
Return task named ``name`` plus its configuration dict.
E.g. in a deeply nested tree, this method returns the `.Task`, and a
configuration dict created by merging that of this `.Collection` and
any nested `Collections <.Collection>`, up through the one actually
holding the `.Task`.
See `~.Collection.__getitem__` for semantics of the ``name`` argument.
:returns: Two-tuple of (`.Task`, `dict`).
"""
# Our top level configuration
ours = self.configuration()
# Default task for this collection itself
if not name:
if self.default:
return self[self.default], ours
else:
raise ValueError("This collection has no default task.")
# Non-default tasks within subcollections -> recurse (sorta)
if '.' in name:
coll, rest = self.split_path(name)
return self._task_with_merged_config(coll, rest, ours)
# Default task for subcollections (via empty-name lookup)
if name in self.collections:
return self._task_with_merged_config(name, '', ours)
# Regular task lookup
return self.tasks[name], ours
def __contains__(self, name):
try:
self[name]
return True
except KeyError:
return False
def to_contexts(self):
"""
Returns all contained tasks and subtasks as a list of parser contexts.
"""
result = []
for primary, aliases in six.iteritems(self.task_names):
task = self[primary]
result.append(ParserContext(
name=primary, aliases=aliases, args=task.get_arguments()
))
return result
def subtask_name(self, collection_name, task_name):
return '.'.join([collection_name, task_name])
@property
def task_names(self):
"""
Return all task identifiers for this collection as a dict.
Specifically, a dict with the primary/"real" task names as the key, and
any aliases as a list value.
"""
ret = {}
# Our own tasks get no prefix, just go in as-is: {name: [aliases]}
for name, task in six.iteritems(self.tasks):
ret[name] = task.aliases
# Subcollection tasks get both name + aliases prefixed
for coll_name, coll in six.iteritems(self.collections):
for task_name, aliases in six.iteritems(coll.task_names):
# Cast to list to handle Py3 map() 'map' return value,
# so we can add to it down below if necessary.
aliases = list(map(
lambda x: self.subtask_name(coll_name, x),
aliases
))
# Tack on collection name to alias list if this task is the
# collection's default.
if coll.default and coll.default == task_name:
aliases += (coll_name,)
ret[self.subtask_name(coll_name, task_name)] = aliases
return ret
def configuration(self, taskpath=None):
"""
Obtain merged configuration values from collection & children.
:param taskpath:
(Optional) Task name/path, identical to that used for
`~.Collection.__getitem__` (e.g. may be dotted for nested tasks,
etc.) Used to decide which path to follow in the collection tree
when merging config values.
:returns: A `dict` containing configuration values.
"""
if taskpath is None:
return copy_dict(self._configuration)
return self.task_with_config(taskpath)[1]
def configure(self, options):
"""
(Recursively) merge ``options`` into the current `.configuration`.
Options configured this way will be available to all tasks. It is
recommended to use unique keys to avoid potential clashes with other
config options
For example, if you were configuring a Sphinx docs build target
directory, it's better to use a key like ``'sphinx.target'`` than
simply ``'target'``.
:param options: An object implementing the dictionary protocol.
:returns: ``None``.
"""
merge_dicts(self._configuration, options)
class Collection(object):
"""
A collection of executable tasks.
"""
def __init__(self, *args, **kwargs):
"""
Create a new task collection/namespace.
`.Collection` offers a set of methods for building a collection of
tasks from scratch, plus a convenient constructor wrapping said API.
In either case:
* the first positional argument may be a string, which (if given) is
used as the collection's default name when performing namespace
lookups;
* a ``loaded_from`` keyword argument may be given, which sets metadata
indicating the filesystem path the collection was loaded from. This
is used as a guide when loading per-project :ref:`configuration files
<config-hierarchy>`.
**The method approach**
May initialize with no arguments and use methods (e.g.
`.add_task`/`.add_collection`) to insert objects::
c = Collection()
c.add_task(some_task)
If an initial string argument is given, it is used as the default name
for this collection, should it be inserted into another collection as a
sub-namespace::
docs = Collection('docs')
docs.add_task(doc_task)
ns = Collection()
ns.add_task(top_level_task)
ns.add_collection(docs)
# Valid identifiers are now 'top_level_task' and 'docs.doc_task'
# (assuming the task objects were actually named the same as the
# variables we're using :))
For details, see the API docs for the rest of the class.
**The constructor approach**
All ``*args`` given to `.Collection` (besides the abovementioned
optional positional 'name' argument and ``loaded_from`` kwarg) are
expected to be `.Task` or `.Collection` instances which will be passed
to `.add_task`/`.add_collection` as appropriate. Module objects are
also valid (as they are for `.add_collection`). For example, the below
snippet results in the same two task identifiers as the one above::
ns = Collection(top_level_task, Collection('docs', doc_task))
If any ``**kwargs`` are given, the keywords are used as the initial
name arguments for the respective values::
ns = Collection(
top_level_task=some_other_task,
docs=Collection(doc_task)
)
That's exactly equivalent to::
docs = Collection(doc_task)
ns = Collection()
ns.add_task(some_other_task, 'top_level_task')
ns.add_collection(docs, 'docs')
See individual methods' API docs for details.
"""
# Initialize
self.tasks = Lexicon()
self.collections = Lexicon()
self.default = None
self.name = None
self._configuration = {}
# Name if applicable
args = list(args)
if args and isinstance(args[0], six.string_types):
self.name = args.pop(0)
# Specific kwargs if applicable
self.loaded_from = kwargs.pop('loaded_from', None)
# Dispatch args/kwargs
for arg in args:
self._add_object(arg)
# Dispatch kwargs
for name, obj in six.iteritems(kwargs):
self._add_object(obj, name)
def _add_object(self, obj, name=None):
if isinstance(obj, Task):
method = self.add_task
elif isinstance(obj, (Collection, types.ModuleType)):
method = self.add_collection
else:
raise TypeError("No idea how to insert {0!r}!".format(type(obj)))
return method(obj, name=name)
def __str__(self):
return "<Collection {0!r}: {1}>".format(
self.name, ", ".join(sorted(self.tasks.keys())))
def __repr__(self):
return str(self)
def __eq__(self, other):
return self.name == other.name and self.tasks == other.tasks
@classmethod
def from_module(self, module, name=None, config=None, loaded_from=None):
"""
Return a new `.Collection` created from ``module``.
Inspects ``module`` for any `.Task` instances and adds them to a new
`.Collection`, returning it. If any explicit namespace collections
exist (named ``ns`` or ``namespace``) a copy of that collection object
is preferentially loaded instead.
When the implicit/default collection is generated, it will be named
after the module's ``__name__`` attribute, or its last dotted section
if it's a submodule. (I.e. it should usually map to the actual ``.py``
filename.)
Explicitly given collections will only be given that module-derived
name if they don't already have a valid ``.name`` attribute.
:param str name:
A string, which if given will override any automatically derived
collection name (or name set on the module's root namespace, if it
has one.)
:param dict config:
Used to set config options on the newly created `.Collection`
before returning it (saving you a call to `.configure`.)
If the imported module had a root namespace object, ``config`` is
merged on top of it (i.e. overriding any conflicts.)
:param str loaded_from:
Identical to the same-named kwarg from the regular class
constructor - should be the path where the module was
found.
"""
module_name = module.__name__.split('.')[-1]
# See if the module provides a default NS to use in lieu of creating
# our own collection.
for candidate in ('ns', 'namespace'):
obj = getattr(module, candidate, None)
if obj and isinstance(obj, Collection):
# TODO: make this into Collection.clone() or similar
# Explicitly given name wins over root ns name which wins over
# actual module name.
ret = Collection(name or obj.name or module_name,
loaded_from=loaded_from)
ret.tasks = copy.deepcopy(obj.tasks)
ret.collections = copy.deepcopy(obj.collections)
ret.default = copy.deepcopy(obj.default)
# Explicitly given config wins over root ns config
obj_config = copy.deepcopy(obj._configuration)
if config:
merge_dicts(obj_config, config)
ret._configuration = obj_config
return ret
# Failing that, make our own collection from the module's tasks.
tasks = filter(lambda x: isinstance(x, Task), vars(module).values())
# Again, explicit name wins over implicit one from module path
collection = Collection(name or module_name, loaded_from=loaded_from)
for task in tasks:
collection.add_task(task)
if config:
collection.configure(config)
return collection
def add_task(self, task, name=None, default=None):
"""
Add `.Task` ``task`` to this collection.
:param task: The `.Task` object to add to this collection.
:param name:
Optional string name to bind to (overrides the task's own
self-defined ``name`` attribute and/or any Python identifier (i.e.
``.func_name``.)
:param default: Whether this task should be the collection default.
"""
if name is None:
if task.name:
name = task.name
elif hasattr(task.body, 'func_name'):
name = task.body.func_name
elif hasattr(task.body, '__name__'):
name = task.__name__
else:
raise ValueError("Could not obtain a name for this task!")
if name in self.collections:
raise ValueError(
"Name conflict: this collection has a sub-collection named {0!r} already"
.format(name)) # noqa
self.tasks[name] = task
for alias in task.aliases:
self.tasks.alias(alias, to=name)
if default is True or (default is None and task.is_default):
if self.default:
msg = "'{0}' cannot be the default because '{1}' already is!"
raise ValueError(msg.format(name, self.default))
self.default = name
def add_collection(self, coll, name=None):
"""
Add `.Collection` ``coll`` as a sub-collection of this one.
:param coll: The `.Collection` to add.
:param str name:
The name to attach the collection as. Defaults to the collection's
own internal name.
"""
# Handle module-as-collection
if isinstance(coll, types.ModuleType):
coll = Collection.from_module(coll)
# Ensure we have a name, or die trying
name = name or coll.name
if not name:
raise ValueError("Non-root collections must have a name!")
# Test for conflict
if name in self.tasks:
raise ValueError(
"Name conflict: this collection has a task named {0!r} already"
.format(name)) # noqa
# Insert
self.collections[name] = coll
def split_path(self, path):
"""
Obtain first collection + remainder, of a task path.
E.g. for ``"subcollection.taskname"``, return ``("subcollection",
"taskname")``; for ``"subcollection.nested.taskname"`` return
``("subcollection", "nested.taskname")``, etc.
An empty path becomes simply ``('', '')``.
"""
parts = path.split('.')
coll = parts.pop(0)
rest = '.'.join(parts)
return coll, rest
def __getitem__(self, name=None):
"""
Returns task named ``name``. Honors aliases and subcollections.
If this collection has a default task, it is returned when ``name`` is
empty or ``None``. If empty input is given and no task has been
selected as the default, ValueError will be raised.
Tasks within subcollections should be given in dotted form, e.g.
'foo.bar'. Subcollection default tasks will be returned on the
subcollection's name.
"""
return self.task_with_config(name)[0]
def _task_with_merged_config(self, coll, rest, ours):
task, config = self.collections[coll].task_with_config(rest)
return task, dict(config, **ours)
def task_with_config(self, name):
"""
Return task named ``name`` plus its configuration dict.
E.g. in a deeply nested tree, this method returns the `.Task`, and a
configuration dict created by merging that of this `.Collection` and
any nested `Collections <.Collection>`, up through the one actually
holding the `.Task`.
See `~.Collection.__getitem__` for semantics of the ``name`` argument.
:returns: Two-tuple of (`.Task`, `dict`).
"""
# Our top level configuration
ours = self.configuration()
# Default task for this collection itself
if not name:
if self.default:
return self[self.default], ours
else:
raise ValueError("This collection has no default task.")
# Non-default tasks within subcollections -> recurse (sorta)
if '.' in name:
coll, rest = self.split_path(name)
return self._task_with_merged_config(coll, rest, ours)
# Default task for subcollections (via empty-name lookup)
if name in self.collections:
return self._task_with_merged_config(name, '', ours)
# Regular task lookup
return self.tasks[name], ours
def __contains__(self, name):
try:
self[name]
return True
except KeyError:
return False
def to_contexts(self):
"""
Returns all contained tasks and subtasks as a list of parser contexts.
"""
result = []
for primary, aliases in six.iteritems(self.task_names):
task = self[primary]
result.append(
ParserContext(name=primary,
aliases=aliases,
args=task.get_arguments()))
return result
def subtask_name(self, collection_name, task_name):
return '.'.join([collection_name, task_name])
@property
def task_names(self):
"""
Return all task identifiers for this collection as a dict.
Specifically, a dict with the primary/"real" task names as the key, and
any aliases as a list value.
"""
ret = {}
# Our own tasks get no prefix, just go in as-is: {name: [aliases]}
for name, task in six.iteritems(self.tasks):
ret[name] = task.aliases
# Subcollection tasks get both name + aliases prefixed
for coll_name, coll in six.iteritems(self.collections):
for task_name, aliases in six.iteritems(coll.task_names):
# Cast to list to handle Py3 map() 'map' return value,
# so we can add to it down below if necessary.
aliases = list(
map(lambda x: self.subtask_name(coll_name, x), aliases))
# Tack on collection name to alias list if this task is the
# collection's default.
if coll.default and coll.default == task_name:
aliases += (coll_name, )
ret[self.subtask_name(coll_name, task_name)] = aliases
return ret
def configuration(self, taskpath=None):
"""
Obtain merged configuration values from collection & children.
.. note::
Merging uses ``copy.deepcopy`` to prevent state bleed.
:param taskpath:
(Optional) Task name/path, identical to that used for
`~.Collection.__getitem__` (e.g. may be dotted for nested tasks,
etc.) Used to decide which path to follow in the collection tree
when merging config values.
:returns: A `dict` containing configuration values.
"""
if taskpath is None:
return copy.deepcopy(self._configuration)
return self.task_with_config(taskpath)[1]
def configure(self, options):
"""
(Recursively) merge ``options`` into the current `.configuration`.
Options configured this way will be available to all tasks. It is
recommended to use unique keys to avoid potential clashes with other
config options
For example, if you were configuring a Sphinx docs build target
directory, it's better to use a key like ``'sphinx.target'`` than
simply ``'target'``.
:param options: An object implementing the dictionary protocol.
:returns: ``None``.
"""
merge_dicts(self._configuration, options)
class ParserContext(object):
"""
Parsing context with knowledge of flags & their format.
Generally associated with the core program or a task.
When run through a parser, will also hold runtime values filled in by the
parser.
"""
def __init__(self, name=None, aliases=(), args=()):
"""
Create a new ``ParserContext`` named ``name``, with ``aliases``.
``name`` is optional, and should be a string if given. It's used to
tell ParserContext objects apart, and for use in a Parser when
determining what chunk of input might belong to a given ParserContext.
``aliases`` is also optional and should be an iterable containing
strings. Parsing will honor any aliases when trying to "find" a given
context in its input.
May give one or more ``args``, which is a quick alternative to calling
``for arg in args: self.add_arg(arg)`` after initialization.
"""
self.args = Lexicon()
self.positional_args = []
self.flags = Lexicon()
self.inverse_flags = {} # No need for Lexicon here
self.name = name
self.aliases = aliases
for arg in args:
self.add_arg(arg)
def __repr__(self):
aliases = ""
if self.aliases:
aliases = " ({0})".format(', '.join(self.aliases))
name = (" {0!r}{1}".format(self.name, aliases)) if self.name else ""
args = (": {0!r}".format(self.args)) if self.args else ""
return "<parser/Context{0}{1}>".format(name, args)
def add_arg(self, *args, **kwargs):
"""
Adds given ``Argument`` (or constructor args for one) to this context.
The Argument in question is added to the following dict attributes:
* ``args``: "normal" access, i.e. the given names are directly exposed
as keys.
* ``flags``: "flaglike" access, i.e. the given names are translated
into CLI flags, e.g. ``"foo"`` is accessible via ``flags['--foo']``.
* ``inverse_flags``: similar to ``flags`` but containing only the
"inverse" versions of boolean flags which default to True. This
allows the parser to track e.g. ``--no-myflag`` and turn it into a
False value for the ``myflag`` Argument.
"""
# Normalize
if len(args) == 1 and isinstance(args[0], Argument):
arg = args[0]
else:
arg = Argument(*args, **kwargs)
# Uniqueness constraint: no name collisions
for name in arg.names:
if name in self.args:
msg = "Tried to add an argument named {0!r} but one already exists!" # noqa
raise ValueError(msg.format(name))
# First name used as "main" name for purposes of aliasing
main = arg.names[0] # NOT arg.name
self.args[main] = arg
# Note positionals in distinct, ordered list attribute
if arg.positional:
self.positional_args.append(arg)
# Add names & nicknames to flags, args
self.flags[to_flag(main)] = arg
for name in arg.nicknames:
self.args.alias(name, to=main)
self.flags.alias(to_flag(name), to=to_flag(main))
# Add attr_name to args, but not flags
if arg.attr_name:
self.args.alias(arg.attr_name, to=main)
# Add to inverse_flags if required
if arg.kind == bool and arg.default is True:
# Invert the 'main' flag name here, which will be a dashed version
# of the primary argument name if underscore-to-dash transformation
# occurred.
inverse_name = to_flag("no-{0}".format(main))
self.inverse_flags[inverse_name] = to_flag(main)
@property
def needs_positional_arg(self):
return any(x.value is None for x in self.positional_args)
@property
def as_kwargs(self):
"""
This context's arguments' values keyed by their ``.name`` attribute.
Results in a dict suitable for use in Python contexts, where e.g. an
arg named ``foo-bar`` becomes accessible as ``foo_bar``.
"""
ret = {}
for arg in self.args.values():
ret[arg.name] = arg.value
return ret
def names_for(self, flag):
# TODO: should probably be a method on Lexicon/AliasDict
return list(set([flag] + self.flags.aliases_of(flag)))
def help_for(self, flag):
"""
Return 2-tuple of ``(flag-spec, help-string)`` for given ``flag``.
"""
# Obtain arg obj
if flag not in self.flags:
err = "{0!r} is not a valid flag for this context! Valid flags are: {1!r}" # noqa
raise ValueError(err.format(flag, self.flags.keys()))
arg = self.flags[flag]
# Determine expected value type, if any
value = {
str: 'STRING',
}.get(arg.kind)
# Format & go
full_names = []
for name in self.names_for(flag):
if value:
# Short flags are -f VAL, long are --foo=VAL
# When optional, also, -f [VAL] and --foo[=VAL]
if len(name.strip('-')) == 1:
value_ = ("[{0}]".format(value)) if arg.optional else value
valuestr = " {0}".format(value_)
else:
valuestr = "={0}".format(value)
if arg.optional:
valuestr = "[{0}]".format(valuestr)
else:
# no value => boolean
# check for inverse
if name in self.inverse_flags.values():
name = "--[no-]{0}".format(name[2:])
valuestr = ""
# Tack together
full_names.append(name + valuestr)
namestr = ", ".join(sorted(full_names, key=len))
helpstr = arg.help or ""
return namestr, helpstr
def help_tuples(self):
"""
Return sorted iterable of help tuples for all member Arguments.
Sorts like so:
* General sort is alphanumerically
* Short flags win over long flags
* Arguments with *only* long flags and *no* short flags will come
first.
* When an Argument has multiple long or short flags, it will sort using
the most favorable (lowest alphabetically) candidate.
This will result in a help list like so::
--alpha, --zeta # 'alpha' wins
--beta
-a, --query # short flag wins
-b, --argh
-c
"""
# TODO: argument/flag API must change :(
# having to call to_flag on 1st name of an Argument is just dumb.
# To pass in an Argument object to help_for may require moderate
# changes?
# Cast to list to ensure non-generator on Python 3.
return list(map(
lambda x: self.help_for(to_flag(x.name)),
sorted(self.flags.values(), key=flag_key)
))
def flag_names(self):
"""
Similar to `help_tuples` but returns flag names only, no helpstrs.
Specifically, all flag names, flattened, in rough order.
"""
# Regular flag names
flags = sorted(self.flags.values(), key=flag_key)
names = [self.names_for(to_flag(x.name)) for x in flags]
# Inverse flag names sold separately
names.append(self.inverse_flags.keys())
return tuple(itertools.chain.from_iterable(names))
