forked from s_ranjbar/city_retrofit
50 lines
1.2 KiB
Python
50 lines
1.2 KiB
Python
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"""
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exceptions.py
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----------------
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Handle things related to exceptions.
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"""
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class ExceptionModule(object):
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"""
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Create a dummy module which will raise an exception when attributes
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are accessed.
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For soft dependencies we want to survive failing to import but
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we would like to raise an appropriate error when the functionality is
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actually requested so the user gets an easily debuggable message.
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"""
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def __init__(self, exc):
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self.exc = exc
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def __getattribute__(self, *args, **kwargs):
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# if it's asking for our class type return None
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# this allows isinstance() checks to not re-raise
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if args[0] == '__class__':
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return None.__class__
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# otherwise raise our original exception
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raise super(ExceptionModule, self).__getattribute__('exc')
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def closure(exc):
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"""
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Return a function which will accept any arguments
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but raise the exception when called.
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Parameters
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------------
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exc : Exception
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Will be raised later
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Returns
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-------------
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failed : function
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When called will raise `exc`
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"""
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# scoping will save exception
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def failed(*args, **kwargs):
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raise exc
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return failed
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