_Columns slicing returns single _Column

[JozsefKutas]

Slicing a _Columns instance returns a single _Column:

import docx

document = docx.Document()
table = document.add_table(3, 3)
print(table.columns[1:])  # shows <docx.table._Column...>

This is similar to the behaviour for table rows raised in #84. Slicing a _Rows instance now returns a list of _Row's as expected, but this behaviour doesn't seem to be implemented by _Columns.

I had a look in table.py and it seems like _Columns and _Rows are implemented in quite different ways. This also leads to other inconsistencies, e.g. the error messages if indexes are out of bounds are different. Is there any reason for this?

My current workaround is to imitate the approach taken in _Rows:

print(list(table.columns)[1:])  # shows [<docx.table._Column ...>, <docx.table._Column ...>]

[scanny]

No, no special reason. It would be better with slicing behavior.