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Created February 28, 2010 03:44
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Use Python OrderedDict as YAML omap
import yaml
### OrderedDict from <http://pypi.python.org/pypi/ordereddict/1.1>
# Copyright (c) 2009 Raymond Hettinger
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
from UserDict import DictMixin
class OrderedDict(dict, DictMixin):
def __init__(self, *args, **kwds):
if len(args) > 1:
raise TypeError('expected at most 1 arguments, got %d' % len(args))
try:
self.__end
except AttributeError:
self.clear()
self.update(*args, **kwds)
def clear(self):
self.__end = end = []
end += [None, end, end] # sentinel node for doubly linked list
self.__map = {} # key --> [key, prev, next]
dict.clear(self)
def __setitem__(self, key, value):
if key not in self:
end = self.__end
curr = end[1]
curr[2] = end[1] = self.__map[key] = [key, curr, end]
dict.__setitem__(self, key, value)
def __delitem__(self, key):
dict.__delitem__(self, key)
key, prev, next = self.__map.pop(key)
prev[2] = next
next[1] = prev
def __iter__(self):
end = self.__end
curr = end[2]
while curr is not end:
yield curr[0]
curr = curr[2]
def __reversed__(self):
end = self.__end
curr = end[1]
while curr is not end:
yield curr[0]
curr = curr[1]
def popitem(self, last=True):
if not self:
raise KeyError('dictionary is empty')
if last:
key = reversed(self).next()
else:
key = iter(self).next()
value = self.pop(key)
return key, value
def __reduce__(self):
items = [[k, self[k]] for k in self]
tmp = self.__map, self.__end
del self.__map, self.__end
inst_dict = vars(self).copy()
self.__map, self.__end = tmp
if inst_dict:
return (self.__class__, (items,), inst_dict)
return self.__class__, (items,)
def keys(self):
return list(self)
setdefault = DictMixin.setdefault
update = DictMixin.update
pop = DictMixin.pop
values = DictMixin.values
items = DictMixin.items
iterkeys = DictMixin.iterkeys
itervalues = DictMixin.itervalues
iteritems = DictMixin.iteritems
def __repr__(self):
if not self:
return '%s()' % (self.__class__.__name__,)
return '%s(%r)' % (self.__class__.__name__, self.items())
def copy(self):
return self.__class__(self)
@classmethod
def fromkeys(cls, iterable, value=None):
d = cls()
for key in iterable:
d[key] = value
return d
def __eq__(self, other):
if isinstance(other, OrderedDict):
if len(self) != len(other):
return False
for p, q in zip(self.items(), other.items()):
if p != q:
return False
return True
return dict.__eq__(self, other)
def __ne__(self, other):
return not self == other
### Construct OrderedDict
def construct_odict(load, node):
"""This is the same as SafeConstructor.construct_yaml_omap(),
except the data type is changed to OrderedDict() and setitem is
used instead of append in the loop.
>>> yaml.load('''
... !!omap
... - foo: bar
... - mumble: quux
... - baz: gorp
... ''')
OrderedDict([('foo', 'bar'), ('mumble', 'quux'), ('baz', 'gorp')])
>>> yaml.load('''!!omap [ foo: bar, mumble: quux, baz : gorp ]''')
OrderedDict([('foo', 'bar'), ('mumble', 'quux'), ('baz', 'gorp')])
"""
omap = OrderedDict()
yield omap
if not isinstance(node, yaml.SequenceNode):
raise yaml.constructor.ConstructorError(
"while constructing an ordered map",
node.start_mark,
"expected a sequence, but found %s" % node.id, node.start_mark
)
for subnode in node.value:
if not isinstance(subnode, yaml.MappingNode):
raise yaml.constructor.ConstructorError(
"while constructing an ordered map", node.start_mark,
"expected a mapping of length 1, but found %s" % subnode.id,
subnode.start_mark
)
if len(subnode.value) != 1:
raise yaml.constructor.ConstructorError(
"while constructing an ordered map", node.start_mark,
"expected a single mapping item, but found %d items" % len(subnode.value),
subnode.start_mark
)
key_node, value_node = subnode.value[0]
key = load.construct_object(key_node)
value = load.construct_object(value_node)
omap[key] = value
yaml.add_constructor(u'tag:yaml.org,2002:omap', construct_odict)
### Represent OrderedDict
def repr_odict(dumper, data):
"""
>>> data = OrderedDict([('foo', 'bar'), ('mumble', 'quux'), ('baz', 'gorp')])
>>> yaml.dump(data, default_flow_style=False)
'!!omap\\n- foo: bar\\n- mumble: quux\\n- baz: gorp\\n'
>>> yaml.dump(data, default_flow_style=True)
'!!omap [foo: bar, mumble: quux, baz: gorp]\\n'
"""
return repr_pairs(dumper, u'tag:yaml.org,2002:omap', data.iteritems())
yaml.add_representer(OrderedDict, repr_odict)
def repr_pairs(dump, tag, sequence, flow_style=None):
"""This is the same code as BaseRepresenter.represent_sequence(),
but the value passed to dump.represent_data() in the loop is a
dictionary instead of a tuple."""
value = []
node = yaml.SequenceNode(tag, value, flow_style=flow_style)
if dump.alias_key is not None:
dump.represented_objects[dump.alias_key] = node
best_style = True
for (key, val) in sequence:
item = dump.represent_data({key: val})
if not (isinstance(item, yaml.ScalarNode) and not item.style):
best_style = False
value.append(item)
if flow_style is None:
if dump.default_flow_style is not None:
node.flow_style = dump.default_flow_style
else:
node.flow_style = best_style
return node
if __name__ == '__main__':
import doctest
doctest.testmod()
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