bpo-32506: Change dataclasses from OrderedDict to plain dict. (gh-5131) · python/cpython@d138892 (original) (raw)

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`import sys

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`import types

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`from copy import deepcopy

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import collections

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`import inspect

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`all = ['dataclass',

`@@ -448,11 +447,11 @@ def _set_attribute(cls, name, value):

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`def _process_class(cls, repr, eq, order, hash, init, frozen):

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Use an OrderedDict because:

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- Order matters!

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- Derived class fields overwrite base class fields, but the

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order is defined by the base class, which is found first.

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fields = collections.OrderedDict()

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Now that dicts retain insertion order, there's no reason to use

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an ordered dict. I am leveraging that ordering here, because

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derived class fields overwrite base class fields, but the order

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is defined by the base class, which is found first.

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fields = {}

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`# Find our base classes in reverse MRO order, and exclude

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`# ourselves. In reversed order so that more derived classes

`@@ -612,7 +611,8 @@ def fields(class_or_instance):

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`except AttributeError:

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`raise TypeError('must be called with a dataclass type or instance')

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Exclude pseudo-fields.

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Exclude pseudo-fields. Note that fields is sorted by insertion

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order, so the order of the tuple is as the fields were defined.

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`return tuple(f for f in fields.values() if f._field_type is _FIELD)

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`@@ -735,7 +735,7 @@ class C(Base):

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`# Copy namespace since we're going to mutate it.

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`namespace = namespace.copy()

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anns = collections.OrderedDict()

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anns = {}

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`for item in fields:

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`if isinstance(item, str):

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`name = item