diff options
Diffstat (limited to 'lib/sqlalchemy/util/langhelpers.py')
| -rw-r--r-- | lib/sqlalchemy/util/langhelpers.py | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/lib/sqlalchemy/util/langhelpers.py b/lib/sqlalchemy/util/langhelpers.py index 1b277cdee..66c530867 100644 --- a/lib/sqlalchemy/util/langhelpers.py +++ b/lib/sqlalchemy/util/langhelpers.py @@ -1743,14 +1743,28 @@ def attrsetter(attrname): return env["set"] -class EnsureKWArgType(type): +class EnsureKWArg: r"""Apply translation of functions to accept \**kw arguments if they don't already. + Used to ensure cross-compatibility with third party legacy code, for things + like compiler visit methods that need to accept ``**kw`` arguments, + but may have been copied from old code that didn't accept them. + + """ + + ensure_kwarg: str + """a regular expression that indicates method names for which the method + should accept ``**kw`` arguments. + + The class will scan for methods matching the name template and decorate + them if necessary to ensure ``**kw`` parameters are accepted. + """ - def __init__(cls, clsname, bases, clsdict): + def __init_subclass__(cls) -> None: fn_reg = cls.ensure_kwarg + clsdict = cls.__dict__ if fn_reg: for key in clsdict: m = re.match(fn_reg, key) @@ -1758,11 +1772,12 @@ class EnsureKWArgType(type): fn = clsdict[key] spec = compat.inspect_getfullargspec(fn) if not spec.varkw: - clsdict[key] = wrapped = cls._wrap_w_kw(fn) + wrapped = cls._wrap_w_kw(fn) setattr(cls, key, wrapped) - super(EnsureKWArgType, cls).__init__(clsname, bases, clsdict) + super().__init_subclass__() - def _wrap_w_kw(self, fn): + @classmethod + def _wrap_w_kw(cls, fn): def wrap(*arg, **kw): return fn(*arg) |