who_won_connect_four_kata

import pandas as pd
pieces_position_list = ['A_Red', 'B_Yellow', 'A_Red', 'B_Yellow', 'A_Red', 'B_Yellow', 'G_Red', 'B_Yellow']



def check_winner(df, colours = ['Red', 'Yellow']):
    for col in df.columns:
        series = df[col]
        prev, count = '?', 1
        for i in series:
            if prev == i and i in colours:
                count += 1
                if count >= 4:
                    print('winner ', prev, ' row ', series.name)
                    return prev
            else:
                prev = i
                count = 1

def make_arena(pieces_position_list):
    arena = {}
    COLUMNS = ['A', 'B', 'C', 'D', 'E', 'F', 'G']
    for c in COLUMNS:
        arena[c] = []
    colours = set()
    for move in pieces_position_list:
        column, colour = move.split('_')
        arena[column].append(colour)
        colours.add(colour)
    return arena, colours

def make_dataframe(arena):
    df = pd.DataFrame.from_dict(arena, orient='index',format='int').T
    print('-'*8)
    print(df)
    return df


def transform_and_check_winners(df, colours):

    for df in [df.T, df]:
#         print(df)
        winner = check_winner(df, colours)
        if winner:
            return winner


def skew_diagonal(arena, upwards = True):
    arena = arena.copy()
    no_cols = len(arena)
    for i, key in enumerate(arena):
        if upwards:
            each_column = range(no_cols - i)
        else:
            each_column = range(i)
        for col in each_column:
            try:
                arena[key] = [0] + arena[key]
            except IndexError:
                pass
    return arena


def who_is_winner(pieces_position_list):
    print(pieces_position_list)
    print('-'*8)
    for upto in range(4,1+len(pieces_position_list)):
        print('-'*8)
        arena, colours = make_arena(pieces_position_list[:upto])
        df = make_dataframe(arena)
        winner = transform_and_check_winners(df, colours)
        if winner:
            return winner

        for upwards in [True, False]:
            skew_arena = skew_diagonal(arena, upwards)
            df = make_dataframe(skew_arena)
            winner = transform_and_check_winners(df, colours)
            if winner:
                return winner
    return 'Draw'


r = who_is_winner(pieces_position_list)
print(r)

given a record of moves in a game of connect 4, calculate who won - ie: first to have 4 in a row orthogonally, or diagonally.
The record of moves is (for instance): ['A_Red', 'B_Yellow', 'A_Red', ...

• where the first character is the column (A-G) followed by the colour (only ever Red or Yellow)