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author | Mariatta Wijaya <mariatta.wijaya@gmail.com> | 2017-02-06 20:16:58 -0800 |
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committer | Mariatta Wijaya <mariatta.wijaya@gmail.com> | 2017-02-06 20:16:58 -0800 |
commit | da79bcf8ac7ae72218ab023e1ed54390bc1a3a27 (patch) | |
tree | 74845e2dbd9521d9748b9c32f1922f4123083bf3 /Lib/idlelib/delegator.py | |
parent | e3c7e835bdfc97750eb9b7fc0ad2493108c2d438 (diff) | |
parent | 1fe806ac56f8b83694d24ab604eb695d00bc8497 (diff) | |
download | cpython-da79bcf8ac7ae72218ab023e1ed54390bc1a3a27.tar.gz |
Issue #29371: merge with 3.5
Diffstat (limited to 'Lib/idlelib/delegator.py')
-rw-r--r-- | Lib/idlelib/delegator.py | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/Lib/idlelib/delegator.py b/Lib/idlelib/delegator.py new file mode 100644 index 0000000000..dc2a1aaeea --- /dev/null +++ b/Lib/idlelib/delegator.py @@ -0,0 +1,33 @@ +class Delegator: + + def __init__(self, delegate=None): + self.delegate = delegate + self.__cache = set() + # Cache is used to only remove added attributes + # when changing the delegate. + + def __getattr__(self, name): + attr = getattr(self.delegate, name) # May raise AttributeError + setattr(self, name, attr) + self.__cache.add(name) + return attr + + def resetcache(self): + "Removes added attributes while leaving original attributes." + # Function is really about resetting delagator dict + # to original state. Cache is just a means + for key in self.__cache: + try: + delattr(self, key) + except AttributeError: + pass + self.__cache.clear() + + def setdelegate(self, delegate): + "Reset attributes and change delegate." + self.resetcache() + self.delegate = delegate + +if __name__ == '__main__': + from unittest import main + main('idlelib.idle_test.test_delegator', verbosity=2) |