<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def ticker(ctx, market):
 """ Show ticker of a market """

    market = Market(market, bitshares_instance=ctx.bitshares)
    ticker = market.ticker()
    t = [["key", "value"]]
    for key in ticker:
        t.append([key, str(ticker[key])])
    print_table(t)