Module conversion

Defines conversions between Rust and Python types.

Traits

• AsPyPointer
  Returns a borrowed pointer to a Python object.
• FromPyObject
  Extract a type from a Python object.
• FromPyObjectBound
  Expected form of FromPyObject to be used in a future PyO3 release.
• IntoPy
  Defines a conversion from a Rust type to a Python object.
• ToPyObject
  Conversion trait that allows various objects to be converted into PyObject.