delete_cols retaining data from deleted column when adjacent cell is blank

Created originally on Bitbucket by cehess (Chris Hess)

Scenario: A spreadsheet with column A and column B. Column B includes some empty cells.

When column A is deleted, all cells from column B that contain values are properly reflected in their new position in column A. However, blank cells from column B continue to reflect their original data from column A.

Files attached. I did not test how delete_rows behaves in a similar situation.

Attachments: delete_cols_test_out.xlsxdelete_cols_test.pydelete_cols_test.xlsx