Redukce streamu na min a max hodnotu

data = ['X-1', 'Y-1', 'Y-2', 'X0', 'X-2', 'X-4', 'Y0', 'Y3', 'Y6', 'Y66', 'X-3', 'Y-3', 'X-4', 'Y-4', 'X-5', 'Y-5', 'Y-4', 'X-337', 'X-22', 'X-3', 'X-2', 'X-1', 'X0', 'Y0', 'Y100']

def read_seq(position, d_in):
    temp_pos = position
    counter = 1
    first_letter = d_in[position][0]
    values = []
    while temp_pos < len(d_in):
        temp = d_in[temp_pos]
        letter = temp[0]
        value = int(temp[1:])
        if letter != first_letter:
            if len(values) > 1:
                my_min_index = values.index(min(values))
                my_max_index = values.index(max(values))
                if my_min_index < my_max_index:
                    return temp_pos, [first_letter+str(min(values)), first_letter+str(max(values))]
                else:
                    return temp_pos, [first_letter+str(max(values)), first_letter+str(min(values))]
            else:
                return temp_pos, [first_letter+str(values[0])]
        else:
                print(f"{counter:03d}...Pozice: {temp_pos:03d}. Písmeno {letter} s hodnotou {value}")

        values.append(value)
        temp_pos += 1
        counter += 1
    else:
        if len(values) > 1:
            my_min_index = values.index(min(values))
            my_max_index = values.index(max(values))
            if my_min_index < my_max_index:
                return temp_pos, [first_letter+str(min(values)), first_letter+str(max(values))]
            else:
                return temp_pos, [first_letter+str(max(values)), first_letter+str(min(values))]
        else:
            return temp_pos, [first_letter+str(values[0])]


readed_position = 0
result = []
while len(data) > readed_position:
    print(f"Zpracovávám od {readed_position:03d}... Nová sekvence")
    readed_position, new_minmax = read_seq(readed_position, data)
    result.extend(new_minmax)
    print(f"Zredukovaná sada {result}")