Commit 8f13e12e authored by Georgios D. Tsoukalas's avatar Georgios D. Tsoukalas
Browse files

common: get/set/del path utility for nested dicts

parent 196d681a
# Copyright 2012 GRNET S.A. All rights reserved.
# Copyright 2012, 2013 GRNET S.A. All rights reserved.
#
# Redistribution and use in source and binary forms, with or
# without modification, are permitted provided that the following
......@@ -76,12 +76,12 @@ def case_unique(iterable):
"""
Compare case uniquness across iterable contents. Return diff.
>>> case_compare(['a','b','c'])
>>> case_unique(['a','b','c'])
[]
>>> case_compaer(['a','A','b','c'])
>>> case_unique(['a','A','b','c'])
['A']
"""
icase = set(map(unicode.lower, iterable))
icase = set(map(unicode.lower, unicode(iterable)))
same = len(icase) == len(iterable)
if not same:
return list(set(iterable) - set(icase))
......
# Copyright 2013 GRNET S.A. All rights reserved.
#
# Redistribution and use in source and binary forms, with or
# without modification, are permitted provided that the following
# conditions are met:
#
# 1. Redistributions of source code must retain the above
# copyright notice, this list of conditions and the following
# disclaimer.
#
# 2. Redistributions in binary form must reproduce the above
# copyright notice, this list of conditions and the following
# disclaimer in the documentation and/or other materials
# provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# The views and conclusions contained in the software and
# documentation are those of the authors and should not be
# interpreted as representing official policies, either expressed
# or implied, of GRNET S.A.
def lookup_path(container, path, sep='.', createpath=False):
"""
return (['a','b'],
[container['a'], container['a']['b']],
'c') where path=sep.join(['a','b','c'])
"""
names = path.split(sep)
dirnames = names[:-1]
basename = names[-1]
node = container
name_path = []
node_path = [node]
for name in dirnames:
name_path.append(name)
if name not in node:
if not createpath:
m = "'{0}': path not found".format(sep.join(name_path))
raise KeyError(m)
node[name] = {}
try:
node = node[name]
except TypeError as e:
m = "'{0}': cannot traverse path beyond this node: {1}"
m = m.format(sep.join(name_path), str(e))
raise ValueError(m)
node_path.append(node)
return name_path, node_path, basename
def walk_paths(container):
for name, node in container.iteritems():
if not hasattr(node, 'items'):
yield [name], [node]
else:
for names, nodes in walk_paths(node):
yield [name] + names, [node] + nodes
def list_paths(container, sep='.'):
"""
>>> sorted(list_paths({'a': {'b': {'c': 'd'}}}))
[('a.b.c', 'd')]
>>> sorted(list_paths({'a': {'b': {'c': 'd'}, 'e': 3}}))
[('a.b.c', 'd'), ('a.e', 3)]
>>> sorted(list_paths({'a': {'b': {'c': 'd'}, 'e': {'f': 3}}}))
[('a.b.c', 'd'), ('a.e.f', 3)]
>>> list_paths({})
[]
"""
return [(sep.join(name_path), node_path[-1])
for name_path, node_path in walk_paths(container)]
def del_path(container, path, sep='.', collect=True):
"""
del container['a']['b']['c'] where path=sep.join(['a','b','c'])
>>> d = {'a': {'b': {'c': 'd'}}}; del_path(d, 'a.b.c'); d
{}
>>> d = {'a': {'b': {'c': 'd'}}}; del_path(d, 'a.b.c', collect=False); d
{'a': {'b': {}}}
>>> d = {'a': {'b': {'c': 'd'}}}; del_path(d, 'a.b.c.d')
Traceback (most recent call last):
ValueError: 'a.b.c': cannot traverse path beyond this node:\
'str' object does not support item deletion
"""
name_path, node_path, basename = \
lookup_path(container, path, sep=sep, createpath=False)
lastnode = node_path.pop()
lastname = basename
try:
if basename in lastnode:
del lastnode[basename]
except (TypeError, KeyError) as e:
m = "'{0}': cannot traverse path beyond this node: {1}"
m = m.format(sep.join(name_path), str(e))
raise ValueError(m)
if collect:
while node_path and not lastnode:
basename = name_path.pop()
lastnode = node_path.pop()
del lastnode[basename]
def get_path(container, path, sep='.'):
"""
return container['a']['b']['c'] where path=sep.join(['a','b','c'])
>>> get_path({'a': {'b': {'c': 'd'}}}, 'a.b.c.d')
Traceback (most recent call last):
ValueError: 'a.b.c.d': cannot traverse path beyond this node:\
string indices must be integers, not str
>>> get_path({'a': {'b': {'c': 1}}}, 'a.b.c.d')
Traceback (most recent call last):
ValueError: 'a.b.c.d': cannot traverse path beyond this node:\
'int' object is unsubscriptable
>>> get_path({'a': {'b': {'c': 1}}}, 'a.b.c')
1
>>> get_path({'a': {'b': {'c': 1}}}, 'a.b')
{'c': 1}
"""
name_path, node_path, basename = \
lookup_path(container, path, sep=sep, createpath=False)
name_path.append(basename)
node = node_path[-1]
try:
return node[basename]
except TypeError as e:
m = "'{0}': cannot traverse path beyond this node: {1}"
m = m.format(sep.join(name_path), str(e))
raise ValueError(m)
except KeyError as e:
m = "'{0}': path not found: {1}"
m = m.format(sep.join(name_path), str(e))
raise KeyError(m)
def set_path(container, path, value, sep='.',
createpath=False, overwrite=True):
"""
container['a']['b']['c'] = value where path=sep.join(['a','b','c'])
>>> set_path({'a': {'b': {'c': 'd'}}}, 'a.b.c.d', 1)
Traceback (most recent call last):
ValueError: 'a.b.c.d': cannot traverse path beyond this node:\
'str' object does not support item assignment
>>> set_path({'a': {'b': {'c': 'd'}}}, 'a.b.x.d', 1)
Traceback (most recent call last):
KeyError: "'a.b.x': path not found"
>>> set_path({'a': {'b': {'c': 'd'}}}, 'a.b.x.d', 1, createpath=True)
>>> set_path({'a': {'b': {'c': 'd'}}}, 'a.b.c', 1)
>>> set_path({'a': {'b': {'c': 'd'}}}, 'a.b.c', 1, overwrite=False)
Traceback (most recent call last):
ValueError: will not overwrite path 'a.b.c'
"""
name_path, node_path, basename = \
lookup_path(container, path, sep=sep, createpath=createpath)
name_path.append(basename)
node = node_path[-1]
if basename in node and not overwrite:
m = "will not overwrite path '{0}'".format(path)
raise ValueError(m)
try:
node[basename] = value
except TypeError as e:
m = "'{0}': cannot traverse path beyond this node: {1}"
m = m.format(sep.join(name_path), str(e))
raise ValueError(m)
if __name__ == '__main__':
import doctest
doctest.testmod()
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