Now keep every row of orders, whether or not the city has a stall record

pandas · from merge and join

pd.mergehow=on=left_on/right_onsuffixesindicatorvalidate

Putting the kettle on…

Starting up…

Exercise 2

Now keep every row of orders, whether or not the city has a stall record.

your answer
stuck? the lesson behind it
merge and join
The named side is kept in full — and duplicate keys multiply your rows.