mirror of
https://github.com/graphql-python/graphene.git
synced 2025-04-26 12:33:41 +03:00
87 lines
2.4 KiB
Python
87 lines
2.4 KiB
Python
from functools import wraps
|
|
|
|
|
|
class cached_property(object):
|
|
"""
|
|
A property that is only computed once per instance and then replaces itself
|
|
with an ordinary attribute. Deleting the attribute resets the property.
|
|
Source: https://github.com/bottlepy/bottle/commit/fa7733e075da0d790d809aa3d2f53071897e6f76
|
|
""" # noqa
|
|
|
|
def __init__(self, func):
|
|
self.__doc__ = getattr(func, '__doc__')
|
|
self.func = func
|
|
|
|
def __get__(self, obj, cls):
|
|
if obj is None:
|
|
return self
|
|
value = obj.__dict__[self.func.__name__] = self.func(obj)
|
|
return value
|
|
|
|
|
|
def memoize(fun):
|
|
"""A simple memoize decorator for functions supporting positional args."""
|
|
@wraps(fun)
|
|
def wrapper(*args, **kwargs):
|
|
key = (args, frozenset(sorted(kwargs.items())))
|
|
try:
|
|
return cache[key]
|
|
except KeyError:
|
|
ret = cache[key] = fun(*args, **kwargs)
|
|
return ret
|
|
cache = {}
|
|
return wrapper
|
|
|
|
|
|
# From this response in Stackoverflow
|
|
# http://stackoverflow.com/a/19053800/1072990
|
|
def to_camel_case(snake_str):
|
|
components = snake_str.split('_')
|
|
# We capitalize the first letter of each component except the first one
|
|
# with the 'title' method and join them together.
|
|
return components[0] + "".join(x.title() for x in components[1:])
|
|
|
|
|
|
class LazyMap(object):
|
|
def __init__(self, origin, _map, state=None):
|
|
self._origin = origin
|
|
self._origin_iter = origin.__iter__()
|
|
self._state = state or []
|
|
self._finished = False
|
|
self._map = _map
|
|
|
|
def __iter__(self):
|
|
return self if not self._finished else iter(self._state)
|
|
|
|
def iter(self):
|
|
return self.__iter__()
|
|
|
|
def __len__(self):
|
|
return self._origin.__len__()
|
|
|
|
def __next__(self):
|
|
try:
|
|
n = next(self._origin_iter)
|
|
n = self._map(n)
|
|
except StopIteration as e:
|
|
self._finished = True
|
|
raise e
|
|
else:
|
|
self._state.append(n)
|
|
return n
|
|
|
|
def next(self):
|
|
return self.__next__()
|
|
|
|
def __getitem__(self, key):
|
|
item = self._origin.__getitem__(key)
|
|
if isinstance(key, slice):
|
|
return LazyMap(item, self._map)
|
|
return self._map(item)
|
|
|
|
def __getattr__(self, name):
|
|
return getattr(self._origin, name)
|
|
|
|
def __repr__(self):
|
|
return "<LazyMap %s>" % repr(self._origin)
|