DeprecationWarning: generator '_sep_inserter' raised StopIteration - PEP 479

In Python 3.6.1, I’m experiencing an issue with a DeprecationWarning as shown below:

lib/python3.6/site-packages/natsort/utils.py:366: DeprecationWarning: generator '_sep_inserter' raised StopIteration
  return lambda split_val, val: tuple(split_val)

Code functions and proceeds, however it pops the above DeprecationWarning for every sort.

Appears to be PEP 479 related. As of Python 3.5, StopIteration handling has changed inside generators.

From PEP 479 section on the Transition Plan, it seems like the correct timing as 3.6 is when the non-silent warning was instituted:

Python 3.5: Enable new semantics under __future__ import; silent deprecation warning if StopIteration bubbles out of a generator not under __future__ import.
Python 3.6: Non-silent deprecation warning.
Python 3.7: Enable new semantics everywhere.

The Natsort code itself shows a comment about StopIteration inside of the referenced _sep_inserter method: https://github.com/SethMMorton/natsort/blob/master/natsort/utils.py#L233

# Get the first element. If StopIteration is raised, that's OK.

Seems like we may just need to handle the raised StopIteration exception as outlined in PEP 479 and execute inside a try...except block to catch StopIteration.

[SethMMorton]

This was fixed with merge request #43. I will close the issue when then next version of natsort is released.

[SethMMorton]

Added in version 5.1.0.