Task: Data-transform-reshape (source dataset: Auto-Tables)

Given a table, predict what python pandas transformation may be needed on the given input table. Valid choices for transformation include: {"stack", "wide_to_long", "transpose", "pivot", "explode", "ffill", "subtitles"}. Note that each of these is a common Python Pandas operator. Some transformations can have parameters. Each transformation and its parameters are describe as follows.
 
- stack: collapse homogeneous cols into rows.
@param (int): stack_start_idx: zero-based starting column index of the homogeneous column-group.
@param (int): stack_end_idx: zero-based ending column index of the homogeneous column-group.
 
- wide_to_long: collapse repeating col-groups into rows.
@param (int): wide_to_long_start_idx: zero-based starting column index of the repeating col-groups.
@param (int): wide_to_long_end_idx: zero-based ending column index of the repeating col-groups.
 
- transpose: convert rows to columns and vice versa.
 
- pivot: pivot repeating row-groups into cols.
@param (int): pivot_row_frequency: frequency of repeating row-groups.
 
- ffill: fill structurally empty cells in tables.
@param (int): ffill_end_idx: zero-based ending column index of the columns to be filled.
 
- explode: convert composite cells into atomic values
@param (int): explode_column_idx: zero-based column index of the column to be exploded.
 
- subtitle: convert table subtitles into a column.
 
OUTPUT the predicted transformation name along with its parameters for the given INPUT table in a JSON, e.g., {"transformation": "stack", "stack_start_idx": 1, "stack_end_idx": 5}. If the input table needs multi-step transformations (e.g, ffill followed by stack), list JSON of each transformation sequentially in a list, e.g., [{"transformation": "ffill", "ffill_end_idx": 1}, {"transformation": "stack", "stack_start_idx": 1, "stack_end_idx": 5}]. No explanation is needed.

## Input:
| Role                         | August 21, 2003   | August 28, 2003   | September 5, 2007   | September 11, 2003   | September 19,2007   |
|:-----------------------------|:------------------|:------------------|:--------------------|:---------------------|:--------------------|
| Toastmaster                  | Ken Maclean       | Irina Krylova     |                     |                      |                     |
| Laughmaster                  | Irina Krylova     | Cheryl Wiker      |                     |                      |                     |
| Grammarian                   | Lori Harris       | Martha Darling    |                     |                      |                     |
| Ah Counter                   | Annie Wolock      |                   |                     |                      |                     |
| Timer                        | Richard Miller    | Ken Maclean       |                     |                      |                     |
| Tip Master                   | Rita Barvinok     | Jerry Soranno     |                     |                      |                     |
| Speaker #1                   | Cheryl Wiker      | Stephanie Coleman | Tom Wagner          | Lori Harris          |                     |
| Speaker #2                   | Richard Moss      | Martha Darling    | Irina Krylova       |                      |                     |
| Speaker #3                   | Jerry Soranno     | Ken Maclean       | Martha Darling      |                      |                     |
| Educational Briefing         |                   |                   |                     |                      |                     |
| Evaluator #1                 |                   | Cheryl Wiker      |                     | Rita Barvinok        |                     |
| Evaluator #2                 |                   | Rita Barvinok     |                     |                      |                     |
| Evaluator #3                 |                   |                   |                     |                      |                     |
| Word Master/  Gesture Master | Richard Miller    | Richard Miller    |                     |                      |                     |
| Table Topics Master          | Martha Darling    | Tom Wagner        |                     |                      | Rita Barvinok       |
| General Evaluator            | Rita Barvinok     | Lori Harris       |                     |                      |                     |

## Output:


source: excel_file
label: operator: stack
stack_start_idx: 1
stack_end_idx: 5
alternative_label: operator: transpose
operator: stack
stack_start_idx: 1
stack_end_idx: 16