Source code for py2neo.util
#!/usr/bin/env python
# -*- encoding: utf-8 -*-
# Copyright 2011-2016, Nigel Small
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Utility module
"""
from itertools import cycle, islice
import re
import warnings
from .compat import string
# Word separation patterns for re-casing strings.
WORD_FIRST = re.compile("(.)([A-Z][a-z]+)")
WORD_ALL = re.compile("([a-z0-9])([A-Z])")
def snake_case(s):
words = s.replace("_", " ").replace("-", " ").split()
return "_".join(word.lower() for word in words)
def relationship_case(s):
s1 = WORD_FIRST.sub(r"\1_\2", s)
return WORD_ALL.sub(r"\1_\2", s1).upper()
def label_case(s):
return "".join(word.title() for word in s.split("_"))
def round_robin(*iterables):
""" Cycle through a number of iterables, returning
the next item from each in turn.
round_robin('ABC', 'D', 'EF') --> A D E B F C
Original recipe credited to George Sakkis
Python 2/3 cross-compatibility tweak by Nigel Small
"""
pending = len(iterables)
nexts = cycle(iter(it) for it in iterables)
while pending:
try:
for n in nexts:
yield next(n)
except StopIteration:
pending -= 1
nexts = cycle(islice(nexts, pending))
def deprecated(message):
""" Decorator for deprecating functions and methods.
::
@deprecated("'foo' has been deprecated in favour of 'bar'")
def foo(x):
pass
"""
def f__(f):
def f_(*args, **kwargs):
warnings.warn(message, category=DeprecationWarning, stacklevel=2)
return f(*args, **kwargs)
f_.__name__ = f.__name__
f_.__doc__ = f.__doc__
f_.__dict__.update(f.__dict__)
return f_
return f__
VERSION = re.compile("(\d+\.\d+(\.\d+)?)")
def version_tuple(string):
numbers = VERSION.match(string)
version = [int(n) for n in numbers.group(0).split(".")]
extra = string[len(numbers.group(0)):]
while extra.startswith(".") or extra.startswith("-"):
extra = extra[1:]
if extra:
version += [extra]
return tuple(version)
def is_collection(obj):
""" Returns true for any iterable which is not a string or byte sequence.
"""
if isinstance(obj, string):
return False
try:
iter(obj)
except TypeError:
return False
else:
return True
has_all = lambda iterable, items: all(item in iterable for item in items)
def raise_from(exception, cause):
exception.__cause__ = cause
raise exception
def metaclass(mcs):
def _metaclass(cls):
attributes = cls.__dict__.copy()
slots = attributes.get("__slots__")
if slots is not None:
if isinstance(slots, str):
slots = [slots]
for slot in slots:
attributes.pop(slot)
attributes.pop("__dict__", None)
attributes.pop("__weakref__", None)
return mcs(cls.__name__, cls.__bases__, attributes)
return _metaclass