def setkeys(self, keys):
"""
``setkeys`` all ows you to pass in a new list of keys which will
replace the current set. This must contain the same set of keys, but
need not be in the same order.
If you pass in new keys that don't match, a ``KeyError`` will be
raised.
>>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
>>> d.keys()
[1, 3, 2]
>>> d.setkeys((1, 2, 3))
>>> d
OrderedDict([(1, 3), (2, 1), (3, 2)])
>>> d.setkeys(['a', 'b', 'c'])
Traceback (most recent call last):
KeyError: 'Keylist is not the same as current keylist.'
"""
# FIXME: Efficiency? (use set for Python 2.4 :-)
# NOTE: list(keys) rather than keys[:] because keys[:] returns
# a tuple, if keys is a tuple.
kcopy = list(keys)
kcopy.sort()
self._sequence.sort()
if kcopy != self._sequence:
raise KeyError('Keylist is not the same as current keylist.')
# NOTE: This makes the _sequence attribute a new object, instead
# of changing it in place.
# FIXME: efficiency?
self._sequence = list(keys)
python类keys()的实例源码
def __call__(self):
"""Pretend to be the keys method."""
return self._main._keys()
def __setitem__(self, index, name):
"""
You cannot assign to keys, but you can do slice assignment to re-order
them.
You can only do slice assignment if the new set of keys is a reordering
of the original set.
"""
if isinstance(index, types.SliceType):
# FIXME: efficiency?
# check length is the same
indexes = range(len(self._main._sequence))[index]
if len(indexes) != len(name):
raise ValueError('attempt to assign sequence of size %s '
'to slice of size %s' % (len(name), len(indexes)))
# check they are the same keys
# FIXME: Use set
old_keys = self._main._sequence[index]
new_keys = list(name)
old_keys.sort()
new_keys.sort()
if old_keys != new_keys:
raise KeyError('Keylist is not the same as current keylist.')
orig_vals = [self._main[k] for k in name]
del self._main[index]
vals = zip(indexes, name, orig_vals)
vals.sort()
for i, k, v in vals:
if self._main.strict and k in self._main:
raise ValueError('slice assignment must be from '
'unique keys')
self._main.insert(i, k, v)
else:
raise ValueError('Cannot assign to keys')
### following methods pinched from UserList and adapted ###
def __delitem__(self, i): raise TypeError('Can\'t delete items from keys')
def __iadd__(self, other): raise TypeError('Can\'t add in place to keys')
def __imul__(self, n): raise TypeError('Can\'t multiply keys in place')
def append(self, item): raise TypeError('Can\'t append items to keys')
def insert(self, i, item): raise TypeError('Can\'t insert items into keys')
def remove(self, item): raise TypeError('Can\'t remove items from keys')
def extend(self, other): raise TypeError('Can\'t extend keys')
def __setitem__(self, index, item):
"""Set item at position i to item."""
if isinstance(index, types.SliceType):
# NOTE: item must be an iterable (list of tuples)
self._main[index] = OrderedDict(item)
else:
# FIXME: Does this raise a sensible error?
orig = self._main.keys[index]
key, value = item
if self._main.strict and key in self and (key != orig):
raise ValueError('slice assignment must be from '
'unique keys')
# delete the current one
del self._main[self._main._sequence[index]]
self._main.insert(index, key, value)
def extend(self, other):
# FIXME: is only a true extend if none of the keys already present
for item in other:
key, value = item
self._main[key] = value
def __setattr__(self, name, value):
"""Protect keys, items, and values."""
if not '_att_dict' in self.__dict__:
object.__setattr__(self, name, value)
else:
try:
fun = self._att_dict[name]
except KeyError:
OrderedDict.__setattr__(self, name, value)
else:
fun(value)
def __init__(self, init_val=(), strict=False):
"""
Create a new ordered dictionary. Cannot init from a normal dict,
nor from kwargs, since items order is undefined in those cases.
If the ``strict`` keyword argument is ``True`` (``False`` is the
default) then when doing slice assignment - the ``OrderedDict`` you are
assigning from *must not* contain any keys in the remaining dict.
>>> OrderedDict()
OrderedDict([])
>>> OrderedDict({1: 1})
Traceback (most recent call last):
TypeError: undefined order, cannot get items from dict
>>> OrderedDict({1: 1}.items())
OrderedDict([(1, 1)])
>>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
>>> d
OrderedDict([(1, 3), (3, 2), (2, 1)])
>>> OrderedDict(d)
OrderedDict([(1, 3), (3, 2), (2, 1)])
"""
self.strict = strict
dict.__init__(self)
if isinstance(init_val, OrderedDict):
self._sequence = init_val.keys()
dict.update(self, init_val)
elif isinstance(init_val, dict):
# we lose compatibility with other ordered dict types this way
raise TypeError('undefined order, cannot get items from dict')
else:
self._sequence = []
self.update(init_val)
### Special methods ###
def __delitem__(self, key):
"""
>>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
>>> del d[3]
>>> d
OrderedDict([(1, 3), (2, 1)])
>>> del d[3]
Traceback (most recent call last):
KeyError: 3
>>> d[3] = 2
>>> d
OrderedDict([(1, 3), (2, 1), (3, 2)])
>>> del d[0:1]
>>> d
OrderedDict([(2, 1), (3, 2)])
"""
if isinstance(key, types.SliceType):
# FIXME: efficiency?
keys = self._sequence[key]
for entry in keys:
dict.__delitem__(self, entry)
del self._sequence[key]
else:
# do the dict.__delitem__ *first* as it raises
# the more appropriate error
dict.__delitem__(self, key)
self._sequence.remove(key)
def __setattr__(self, name, value):
"""
Implemented so that accesses to ``sequence`` raise a warning and are
diverted to the new ``setkeys`` method.
"""
if name == 'sequence':
warnings.warn('Use of the sequence attribute is deprecated.'
' Use the keys method instead.', DeprecationWarning)
# NOTE: doesn't return anything
self.setkeys(value)
else:
# FIXME: do we want to allow arbitrary setting of attributes?
# Or do we want to manage it?
object.__setattr__(self, name, value)
def setkeys(self, keys):
"""
``setkeys`` all ows you to pass in a new list of keys which will
replace the current set. This must contain the same set of keys, but
need not be in the same order.
If you pass in new keys that don't match, a ``KeyError`` will be
raised.
>>> d = OrderedDict(((1, 3), (3, 2), (2, 1)))
>>> d.keys()
[1, 3, 2]
>>> d.setkeys((1, 2, 3))
>>> d
OrderedDict([(1, 3), (2, 1), (3, 2)])
>>> d.setkeys(['a', 'b', 'c'])
Traceback (most recent call last):
KeyError: 'Keylist is not the same as current keylist.'
"""
# FIXME: Efficiency? (use set for Python 2.4 :-)
# NOTE: list(keys) rather than keys[:] because keys[:] returns
# a tuple, if keys is a tuple.
kcopy = list(keys)
kcopy.sort()
self._sequence.sort()
if kcopy != self._sequence:
raise KeyError('Keylist is not the same as current keylist.')
# NOTE: This makes the _sequence attribute a new object, instead
# of changing it in place.
# FIXME: efficiency?
self._sequence = list(keys)
def __call__(self):
"""Pretend to be the keys method."""
return self._main._keys()
def __setitem__(self, index, name):
"""
You cannot assign to keys, but you can do slice assignment to re-order
them.
You can only do slice assignment if the new set of keys is a reordering
of the original set.
"""
if isinstance(index, types.SliceType):
# FIXME: efficiency?
# check length is the same
indexes = range(len(self._main._sequence))[index]
if len(indexes) != len(name):
raise ValueError('attempt to assign sequence of size %s '
'to slice of size %s' % (len(name), len(indexes)))
# check they are the same keys
# FIXME: Use set
old_keys = self._main._sequence[index]
new_keys = list(name)
old_keys.sort()
new_keys.sort()
if old_keys != new_keys:
raise KeyError('Keylist is not the same as current keylist.')
orig_vals = [self._main[k] for k in name]
del self._main[index]
vals = zip(indexes, name, orig_vals)
vals.sort()
for i, k, v in vals:
if self._main.strict and k in self._main:
raise ValueError('slice assignment must be from '
'unique keys')
self._main.insert(i, k, v)
else:
raise ValueError('Cannot assign to keys')
### following methods pinched from UserList and adapted ###
def __delitem__(self, i): raise TypeError('Can\'t delete items from keys')
