Deprecation warning when importing on Python 3.10

[domdfcoding]

On Python 3.10.0a3:

Python 3.10.0a3 (default, Dec  8 2020, 03:28:14) 
>>> import tabulate
/tmp/tabulate-venv/lib/python3.10/site-packages/tabulate.py:16: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3, and in 3.10 it will stop working
  from collections import Iterable
>>> 

This was "fixed" in 3bfe294, and indeed there's no warning on 3.8.5:

Python 3.8.5 (default, Jul 28 2020, 12:59:40) 
>>> import tabulate
>>> 

The relevant code is

python-tabulate/tabulate.py

Lines 13 to 16 in 2552e6d

	if python_version_tuple() >= ("3", "3", "0"):
	from collections.abc import Iterable
	else:
	from collections import Iterable

However, the fix is not tolerant to Python 3.10's extra digit -- python_version_tuple() returns ('3', '10', '0a3'), and since these are strings '10' is treated as being less than '3'. The recommended way to perform this is:

if sys.version_info >= (3, 3):
    from collections.abc import Iterable
else:
    from collections import Iterable

since sys.version_info is a tuple of ints, and correctly handles two-digit minor versions.

Happy to submit a PR to fix this, assuming you still want to support Python versions that old?

[hroncok]

This is now a hard ImportError since 3.10.0a5:

ERROR: Failure: ImportError (cannot import name 'Iterable' from 'collections' (/usr/lib64/python3.10/collections/__init__.py))
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/usr/lib/python3.10/site-packages/nose/failure.py", line 39, in runTest
    raise self.exc_val.with_traceback(self.tb)
  File "/usr/lib/python3.10/site-packages/nose/loader.py", line 416, in loadTestsFromName
    module = self.importer.importFromPath(
  File "/usr/lib/python3.10/site-packages/nose/importer.py", line 47, in importFromPath
    return self.importFromDir(dir_path, fqname)
  File "/usr/lib/python3.10/site-packages/nose/importer.py", line 94, in importFromDir
    mod = load_module(part_fqname, fh, filename, desc)
  File "/usr/lib64/python3.10/imp.py", line 234, in load_module
    return load_source(name, filename, file)
  File "/usr/lib64/python3.10/imp.py", line 171, in load_source
    module = _load(spec)
  File "<frozen importlib._bootstrap>", line 729, in _load
  File "<frozen importlib._bootstrap>", line 698, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 833, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/builddir/build/BUILD/tabulate-0.8.7/test/test_regression.py", line 7, in <module>
    from tabulate import tabulate, _text_type, _long_type, TableFormat, Line, DataRow
  File "/builddir/build/BUILD/tabulate-0.8.7/tabulate.py", line 16, in <module>
    from collections import Iterable
ImportError: cannot import name 'Iterable' from 'collections' (/usr/lib64/python3.10/collections/__init__.py)