226 lines
7.9 KiB
Python
226 lines
7.9 KiB
Python
import sys as _sys
|
|
from keyword import iskeyword as _iskeyword
|
|
|
|
|
|
def _validate_names(typename, field_names, extra_field_names):
|
|
"""
|
|
Ensure that all the given names are valid Python identifiers that
|
|
do not start with '_'. Also check that there are no duplicates
|
|
among field_names + extra_field_names.
|
|
"""
|
|
for name in [typename] + field_names + extra_field_names:
|
|
if not isinstance(name, str):
|
|
raise TypeError('typename and all field names must be strings')
|
|
if not name.isidentifier():
|
|
raise ValueError('typename and all field names must be valid '
|
|
f'identifiers: {name!r}')
|
|
if _iskeyword(name):
|
|
raise ValueError('typename and all field names cannot be a '
|
|
f'keyword: {name!r}')
|
|
|
|
seen = set()
|
|
for name in field_names + extra_field_names:
|
|
if name.startswith('_'):
|
|
raise ValueError('Field names cannot start with an underscore: '
|
|
f'{name!r}')
|
|
if name in seen:
|
|
raise ValueError(f'Duplicate field name: {name!r}')
|
|
seen.add(name)
|
|
|
|
|
|
# Note: This code is adapted from CPython:Lib/collections/__init__.py
|
|
def _make_tuple_bunch(typename, field_names, extra_field_names=None,
|
|
module=None):
|
|
"""
|
|
Create a namedtuple-like class with additional attributes.
|
|
|
|
This function creates a subclass of tuple that acts like a namedtuple
|
|
and that has additional attributes.
|
|
|
|
The additional attributes are listed in `extra_field_names`. The
|
|
values assigned to these attributes are not part of the tuple.
|
|
|
|
The reason this function exists is to allow functions in SciPy
|
|
that currently return a tuple or a namedtuple to returned objects
|
|
that have additional attributes, while maintaining backwards
|
|
compatibility.
|
|
|
|
This should only be used to enhance *existing* functions in SciPy.
|
|
New functions are free to create objects as return values without
|
|
having to maintain backwards compatibility with an old tuple or
|
|
namedtuple return value.
|
|
|
|
Parameters
|
|
----------
|
|
typename : str
|
|
The name of the type.
|
|
field_names : list of str
|
|
List of names of the values to be stored in the tuple. These names
|
|
will also be attributes of instances, so the values in the tuple
|
|
can be accessed by indexing or as attributes. At least one name
|
|
is required. See the Notes for additional restrictions.
|
|
extra_field_names : list of str, optional
|
|
List of names of values that will be stored as attributes of the
|
|
object. See the notes for additional restrictions.
|
|
|
|
Returns
|
|
-------
|
|
cls : type
|
|
The new class.
|
|
|
|
Notes
|
|
-----
|
|
There are restrictions on the names that may be used in `field_names`
|
|
and `extra_field_names`:
|
|
|
|
* The names must be unique--no duplicates allowed.
|
|
* The names must be valid Python identifiers, and must not begin with
|
|
an underscore.
|
|
* The names must not be Python keywords (e.g. 'def', 'and', etc., are
|
|
not allowed).
|
|
|
|
Examples
|
|
--------
|
|
>>> from scipy._lib._bunch import _make_tuple_bunch
|
|
|
|
Create a class that acts like a namedtuple with length 2 (with field
|
|
names `x` and `y`) that will also have the attributes `w` and `beta`:
|
|
|
|
>>> Result = _make_tuple_bunch('Result', ['x', 'y'], ['w', 'beta'])
|
|
|
|
`Result` is the new class. We call it with keyword arguments to create
|
|
a new instance with given values.
|
|
|
|
>>> result1 = Result(x=1, y=2, w=99, beta=0.5)
|
|
>>> result1
|
|
Result(x=1, y=2, w=99, beta=0.5)
|
|
|
|
`result1` acts like a tuple of length 2:
|
|
|
|
>>> len(result1)
|
|
2
|
|
>>> result1[:]
|
|
(1, 2)
|
|
|
|
The values assigned when the instance was created are available as
|
|
attributes:
|
|
|
|
>>> result1.y
|
|
2
|
|
>>> result1.beta
|
|
0.5
|
|
"""
|
|
if len(field_names) == 0:
|
|
raise ValueError('field_names must contain at least one name')
|
|
|
|
if extra_field_names is None:
|
|
extra_field_names = []
|
|
_validate_names(typename, field_names, extra_field_names)
|
|
|
|
typename = _sys.intern(str(typename))
|
|
field_names = tuple(map(_sys.intern, field_names))
|
|
extra_field_names = tuple(map(_sys.intern, extra_field_names))
|
|
|
|
all_names = field_names + extra_field_names
|
|
arg_list = ', '.join(field_names)
|
|
full_list = ', '.join(all_names)
|
|
repr_fmt = ''.join(('(',
|
|
', '.join(f'{name}=%({name})r' for name in all_names),
|
|
')'))
|
|
tuple_new = tuple.__new__
|
|
_dict, _tuple, _zip = dict, tuple, zip
|
|
|
|
# Create all the named tuple methods to be added to the class namespace
|
|
|
|
s = f"""\
|
|
def __new__(_cls, {arg_list}, **extra_fields):
|
|
return _tuple_new(_cls, ({arg_list},))
|
|
|
|
def __init__(self, {arg_list}, **extra_fields):
|
|
for key in self._extra_fields:
|
|
if key not in extra_fields:
|
|
raise TypeError("missing keyword argument '%s'" % (key,))
|
|
for key, val in extra_fields.items():
|
|
if key not in self._extra_fields:
|
|
raise TypeError("unexpected keyword argument '%s'" % (key,))
|
|
self.__dict__[key] = val
|
|
|
|
def __setattr__(self, key, val):
|
|
if key in {repr(field_names)}:
|
|
raise AttributeError("can't set attribute %r of class %r"
|
|
% (key, self.__class__.__name__))
|
|
else:
|
|
self.__dict__[key] = val
|
|
"""
|
|
del arg_list
|
|
namespace = {'_tuple_new': tuple_new,
|
|
'__builtins__': dict(TypeError=TypeError,
|
|
AttributeError=AttributeError),
|
|
'__name__': f'namedtuple_{typename}'}
|
|
exec(s, namespace)
|
|
__new__ = namespace['__new__']
|
|
__new__.__doc__ = f'Create new instance of {typename}({full_list})'
|
|
__init__ = namespace['__init__']
|
|
__init__.__doc__ = f'Instantiate instance of {typename}({full_list})'
|
|
__setattr__ = namespace['__setattr__']
|
|
|
|
def __repr__(self):
|
|
'Return a nicely formatted representation string'
|
|
return self.__class__.__name__ + repr_fmt % self._asdict()
|
|
|
|
def _asdict(self):
|
|
'Return a new dict which maps field names to their values.'
|
|
out = _dict(_zip(self._fields, self))
|
|
out.update(self.__dict__)
|
|
return out
|
|
|
|
def __getnewargs_ex__(self):
|
|
'Return self as a plain tuple. Used by copy and pickle.'
|
|
return _tuple(self), self.__dict__
|
|
|
|
# Modify function metadata to help with introspection and debugging
|
|
for method in (__new__, __repr__, _asdict, __getnewargs_ex__):
|
|
method.__qualname__ = f'{typename}.{method.__name__}'
|
|
|
|
# Build-up the class namespace dictionary
|
|
# and use type() to build the result class
|
|
class_namespace = {
|
|
'__doc__': f'{typename}({full_list})',
|
|
'_fields': field_names,
|
|
'__new__': __new__,
|
|
'__init__': __init__,
|
|
'__repr__': __repr__,
|
|
'__setattr__': __setattr__,
|
|
'_asdict': _asdict,
|
|
'_extra_fields': extra_field_names,
|
|
'__getnewargs_ex__': __getnewargs_ex__,
|
|
}
|
|
for index, name in enumerate(field_names):
|
|
|
|
def _get(self, index=index):
|
|
return self[index]
|
|
class_namespace[name] = property(_get)
|
|
for name in extra_field_names:
|
|
|
|
def _get(self, name=name):
|
|
return self.__dict__[name]
|
|
class_namespace[name] = property(_get)
|
|
|
|
result = type(typename, (tuple,), class_namespace)
|
|
|
|
# For pickling to work, the __module__ variable needs to be set to the
|
|
# frame where the named tuple is created. Bypass this step in environments
|
|
# where sys._getframe is not defined (Jython for example) or sys._getframe
|
|
# is not defined for arguments greater than 0 (IronPython), or where the
|
|
# user has specified a particular module.
|
|
if module is None:
|
|
try:
|
|
module = _sys._getframe(1).f_globals.get('__name__', '__main__')
|
|
except (AttributeError, ValueError):
|
|
pass
|
|
if module is not None:
|
|
result.__module__ = module
|
|
__new__.__module__ = module
|
|
|
|
return result
|