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Include memo in the documented signature of copy.deepcopy()
* Include memo in the documented signature of copy.deepcopy() The memo argument is mentioned lower on the doc page under writing a `__deepcopy__` method, but is not included in the documented function signature. This makes it easy to miss, and can lead to incorrect/buggy implementations of `__deepcopy__` -- which is exatly what just happpend to me!
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@ -22,7 +22,7 @@ Interface summary:
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Return a shallow copy of *x*.
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.. function:: deepcopy(x)
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.. function:: deepcopy(x[, memo])
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Return a deep copy of *x*.
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@ -52,7 +52,7 @@ copy operations:
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The :func:`deepcopy` function avoids these problems by:
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* keeping a "memo" dictionary of objects already copied during the current
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* keeping a ``memo`` dictionary of objects already copied during the current
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copying pass; and
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* letting user-defined classes override the copying operation or the set of
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@ -82,7 +82,7 @@ In order for a class to define its own copy implementation, it can define
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special methods :meth:`__copy__` and :meth:`__deepcopy__`. The former is called
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to implement the shallow copy operation; no additional arguments are passed.
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The latter is called to implement the deep copy operation; it is passed one
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argument, the memo dictionary. If the :meth:`__deepcopy__` implementation needs
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argument, the ``memo`` dictionary. If the :meth:`__deepcopy__` implementation needs
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to make a deep copy of a component, it should call the :func:`deepcopy` function
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with the component as first argument and the memo dictionary as second argument.
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