read xlsx in py.py

#!/usr/bin/env ipython

from openpyxl import load_workbook
from toolz import thread_last, curry
import toolz.curried as tc
from typing import List, Dict, Tuple
import os

def list_to_dict_list(all_rows: List[List]) -> List[Dict]:
    """this just chops the headers off the spreadsheet, and then uses them to make
    a dictionary out of the rest of the stuff."""
    headers, *rest = all_rows
    return [dict(zip(headers, x)) for x in rest]


@curry
def fetch_cell_coordinate(ws, coordinate: Tuple[int, int]):
    "Grab a value out of a cell coordinate."
    x, y = coordinate
    return ws.cell(x, y).value


def excel_ws_to_list_of_dicts(filename: str, worksheet: str) -> List[Dict]:
    "Takes a file, and worksheet, and returns a list of dictionaries.  Assumes the xls has a header row."
    assert os.path.isfile(filename), "This doesn't look like a good file to open?"
    wb = load_workbook(filename=filename, read_only=True)
    ws = wb[worksheet]

    # tuple containing all row and cell coordinates.
    # if 3 rows by 4 columns by 8 rows:
    # > [[1, 1],
    #    [1, 2],
    #    [1, 3],
    #    [1, 4],
    #    [2, 1],
    #    [2, 2],
    #    [2, 3],
    #    [2, 4],
    #    [3, 1],
    #    [3, 2],
    #    [3, 3],
    #    [3, 4]]
    cell_coordinates = [[r, c] for r in range(ws.min_row, ws.max_row + 1)
                        for c in range(ws.min_column, ws.max_column + 1)]
    # map all cell coordinates back into partitions of column width size and
    # then yield to list.
    my_fetch_cell_coordinates = fetch_cell_coordinate(ws)
    return thread_last(cell_coordinates,
                       tc.map(my_fetch_cell_coordinates),  # Pick out each value for each cell
                       tc.partition(ws.max_column),        # partition to list of lists
                       list_to_dict_list,               # convert list of lists to list of dicts
                       list)