For regular dicts I like to use the dict() function because the code is easier
to write and read. But OrderedDict() is not equivalent to dict():
In the docstring of collections.OrderedDict it says "keyword arguments are not
recommended because their insertion order is arbitrary"
(https://github.com/python/cpython/blob/3.6/Lib/collections/__init__.py)
It took me while to realize that. What is the best way to use keywords to
create an ordered dict, while maintaining insertion order?
Below is OrderedDict.__init__. Would the insertion order be preserved if the
last line were to be replaced with:
if kwds:
for k, v in kwds.items():
self[k] = v
if args:
self.__update(*args) # no **kwds!
###
class OrderedDict(dict):
'Dictionary that remembers insertion order'
def __init__(*args, **kwds):
'''Initialize an ordered dictionary. The signature is the same as
regular dictionaries, but keyword arguments are not recommended because
their insertion order is arbitrary.
'''
if not args:
raise TypeError("descriptor '__init__' of 'OrderedDict' object "
"needs an argument")
self, *args = args
if len(args) > 1:
raise TypeError('expected at most 1 arguments, got %d' % len(args))
try:
self.__root
except AttributeError:
self.__hardroot = _Link()
self.__root = root = _proxy(self.__hardroot)
root.prev = root.next = root
self.__map = {}
self.__update(*args, **kwds)
Thanks!
Albert-Jan
--
https://mail.python.org/mailman/listinfo/python-list
