#!/usr/bin/env python

# Combines two map spreadsheets A0->B and A1->C to A->B, with A0 overwriting A1

import csv

import sys

def main():

    try: _prog_name, map_1_path = sys.argv

    except ValueError:

        raise SystemExit('Usage: '+sys.argv[0]+' <map_0 map_1 [| '+sys.argv[0]

            +' map_2]... >union_map')

    map_ = {}

    def add_map(reader):

        for row in reader:

            if row[1] != '': map_[row[0]] = row[1:]

    # Get map 1

    stream = open(map_1_path, 'rb')

    reader = csv.reader(stream)

    map_1_cols = reader.next()

    add_map(reader)

    stream.close()

    # Add map 0 to map 1, overwriting existing entries

    reader = csv.reader(sys.stdin)

    map_0_cols = reader.next()

    if not map_0_cols[0] == map_1_cols[0]: raise SystemExit('Map error: '

        'Map 1 column 0 name doesn\'t match map 0 column 0 name')

    add_map(reader)

    # Write combined map

    writer = csv.writer(sys.stdout)

    writer.writerow(map_0_cols)

    for in_, rest in map_.iteritems(): writer.writerow([in_]+rest)

main()