"""

Implementations of standard library functions, because it's not possible to

understand them with Jedi.

To add a new implementation, create a function and add it to the

``_implemented`` dict at the bottom of this module.

"""

import collections

import re

from jedi._compatibility import unicode

from jedi.evaluate import compiled

from jedi.evaluate import representation as er

from jedi.evaluate import iterable

from jedi.parser import Parser

from jedi.parser import tree

from jedi import debug

from jedi.evaluate import precedence

from jedi.evaluate import param

class NotInStdLib(LookupError):

pass

def execute(evaluator, obj, params):

try:

obj_name = str(obj.name)

except AttributeError:

pass

else:

if obj.parent == compiled.builtin:

module_name = 'builtins'

elif isinstance(obj.parent, tree.Module):

module_name = str(obj.parent.name)

else:

module_name = ''

# for now we just support builtin functions.

try:

return _implemented[module_name][obj_name](evaluator, obj, params)

except KeyError:

pass

raise NotInStdLib()

def _follow_param(evaluator, params, index):

try:

key, values = list(params.unpack())[index]

except IndexError:

return []

else:

return iterable.unite(evaluator.eval_element(v) for v in values)

def argument_clinic(string, want_obj=False, want_scope=False):

"""

Works like Argument Clinic (PEP 436), to validate function params.

"""

clinic_args = []

allow_kwargs = False

optional = False

while string:

# Optional arguments have to begin with a bracket. And should always be

# at the end of the arguments. This is therefore not a proper argument

# clinic implementation. `range()` for exmple allows an optional start

# value at the beginning.

match = re.match('(?:(?:(\[),? ?|, ?|)(\w+)|, ?/)\]*', string)

string = string[len(match.group(0)):]

if not match.group(2): # A slash -> allow named arguments

allow_kwargs = True

continue

optional = optional or bool(match.group(1))

word = match.group(2)

clinic_args.append((word, optional, allow_kwargs))

def f(func):

def wrapper(evaluator, obj, arguments):

try:

lst = list(arguments.eval_argument_clinic(clinic_args))

except ValueError:

return []

else:

kwargs = {}

if want_scope:

kwargs['scope'] = arguments.scope()

if want_obj:

kwargs['obj'] = obj

return func(evaluator, *lst, **kwargs)

return wrapper

return f

@argument_clinic('object, name[, default], /')

def builtins_getattr(evaluator, objects, names, defaults=None):

types = []

# follow the first param

for obj in objects:

if not isinstance(obj, (er.Instance, er.Class, tree.Module, compiled.CompiledObject)):

debug.warning('getattr called without instance')

continue

for name in names:

if precedence.is_string(name):

return evaluator.find_types(obj, name.obj)

else:

debug.warning('getattr called without str')

continue

return types

@argument_clinic('object[, bases, dict], /')

def builtins_type(evaluator, objects, bases, dicts):

if bases or dicts:

# metaclass... maybe someday...

return []

else:

return [o.base for o in objects if isinstance(o, er.Instance)]

class SuperInstance(er.Instance):

"""To be used like the object ``super`` returns."""

def __init__(self, evaluator, cls):

su = cls.py_mro()[1]

super().__init__(evaluator, su and su[0] or self)

@argument_clinic('[type[, obj]], /', want_scope=True)

def builtins_super(evaluator, types, objects, scope):

# TODO make this able to detect multiple inheritance super

accept = (tree.Function, er.FunctionExecution)

if scope.isinstance(*accept):

wanted = (tree.Class, er.Instance)

cls = scope.get_parent_until(accept + wanted,

include_current=False)

if isinstance(cls, wanted):

if isinstance(cls, tree.Class):

cls = er.Class(evaluator, cls)

elif isinstance(cls, er.Instance):

cls = cls.base

su = cls.py__bases__(evaluator)

if su:

return evaluator.execute(su[0])

return []

@argument_clinic('sequence, /', want_obj=True)

def builtins_reversed(evaluator, sequences, obj):

# Unpack the iterator values

objects = tuple(iterable.get_iterator_types(sequences))

rev = [iterable.AlreadyEvaluated([o]) for o in reversed(objects)]

# Repack iterator values and then run it the normal way. This is

# necessary, because `reversed` is a function and autocompletion

# would fail in certain cases like `reversed(x).__iter__` if we

# just returned the result directly.

rev = iterable.AlreadyEvaluated(

[iterable.FakeSequence(evaluator, rev, 'list')]

)

return [er.Instance(evaluator, obj, param.Arguments(evaluator, [rev]))]

@argument_clinic('obj, type, /')

def builtins_isinstance(evaluator, objects, types):

bool_results = set([])

for o in objects:

try:

mro_func = o.py__class__(evaluator).py__mro__

except AttributeError:

# This is temporary. Everything should have a class attribute in

# Python?! Maybe we'll leave it here, because some numpy objects or

# whatever might not.

return [compiled.true_obj, compiled.false_obj]

mro = mro_func(evaluator)

for cls_or_tup in types:

if cls_or_tup.is_class():

bool_results.add(cls_or_tup in mro)

else:

# Check for tuples.

classes = iterable.get_iterator_types([cls_or_tup])

bool_results.add(any(cls in mro for cls in classes))

return [compiled.keyword_from_value(x) for x in bool_results]

def collections_namedtuple(evaluator, obj, params):

"""

Implementation of the namedtuple function.

This has to be done by processing the namedtuple class template and

evaluating the result.

.. note:: |jedi| only supports namedtuples on Python >2.6.

"""

# Namedtuples are not supported on Python 2.6

if not hasattr(collections, '_class_template'):

return []

# Process arguments

name = _follow_param(evaluator, params, 0)[0].obj

_fields = _follow_param(evaluator, params, 1)[0]

if isinstance(_fields, compiled.CompiledObject):

fields = _fields.obj.replace(',', ' ').split()

elif isinstance(_fields, iterable.Array):

try:

fields = [v.obj for v in _fields.values()]

except AttributeError:

return []

else:

return []

# Build source

source = collections._class_template.format(

typename=name,

field_names=fields,

num_fields=len(fields),

arg_list=', '.join(fields),

repr_fmt=', '.join(collections._repr_template.format(name=name) for name in fields),

field_defs='\n'.join(collections._field_template.format(index=index, name=name)

for index, name in enumerate(fields))

)

# Parse source

generated_class = Parser(evaluator.grammar, unicode(source)).module.subscopes[0]

return [er.Class(evaluator, generated_class)]

@argument_clinic('first, /')

def _return_first_param(evaluator, firsts):

return firsts

_implemented = {

'builtins': {

'getattr': builtins_getattr,

'type': builtins_type,

'super': builtins_super,

'reversed': builtins_reversed,

'isinstance': builtins_isinstance,

},

'copy': {

'copy': _return_first_param,

'deepcopy': _return_first_param,

},

'json': {

'load': lambda *args: [],

'loads': lambda *args: [],

},

'collections': {

'namedtuple': collections_namedtuple,

},

}