A Portfolio Management $$ System generates a set of Orders $$ throughout the day that need$-$to$-$be traded on a $-$market.

An Order$-$needs to$-$be traded within $10-$minutes. $$ Each trade has an $-$ associated transaction cost, let's say $$1.$ Design a system that$-$would minimize the transaction cost by grouping similar Orders.

$//2017-07-01-15$:$00|$ BUY $|100|$ GOOG

$//2017-07-01-15$:$02|$ BUY $|400|$ MSFT

$//2017-07-01-15$:$05|$ SELL $|300|$ GOOG

$//2017-07-01-15$:$11|$ BUY $|500|$ GS

$//2017-07-01-15$:$11|$ SELL $|100|$ MSFT

$//2017-07-01-15$:$14|$ SELL $|50|$ MSFT

$//$Example Output:

$//2017-07-01-15$:$10|$ SELL $|200|$ GOOG

$//2017-07-01-15$:$12|$ BUY $|300|$ MSFT

$//2017-07-01-15$:$21|$ BUY $|500|$ GS

$//2017-07-01-15$:$24|$ SELL $|50|$ MSFT

$//$ Total.cost : $$4$

$//2017-07-01-15$:$00|$ BUY $|400|$ GOOG

$//2017-07-01-15$:$02|$ BUY $|100|$ MSFT

$//2017-07-01-15$:$04|$ BUY $|100|$ MSFT

$//2017-07-01-15$:$08|$ BUY $|200|$ GS

$//2017-07-01-15$:$12|$ SELL $|200|$ GOOG

$//2017-07-01-15$:$15|$ SELL $|100|$ GOOG

$//2017-07-01-15$:$20|$ BUY $|500|$ GS

$//2017-07-01-15$:$22|$ SELL $|600|$ GS

$//2017-07-01-15$:$25|$ BUY $|100|$ MSFT

$//$Example Output:

$//2017-07-01-15$:$10|$ BUY $|400|$ GOOG

$//2017-07-01-15$:$12|$ BUY $|200|$ MSFT

$//2017-07-01-15$:$18|$ BUY $|200|$ GS

$//2017-07-01-15$:$22|$ SELL $|300|$ GOOG

$//2017-07-01-15$:$35|$ SELL $|100|$ MSFT

$//$ Total.cost : $$5$

Solve this with python.