question 172 Exceptions & Validation · easy

The delay that is always zero

The flights dashboard shows an average departure delay of 0 minutes for every airport, even on stormy days. average_delay should return the mean of the delays, and 0 only when there are no flights. Fix it, and make sure the next typo can't hide the same way.

Functionaverage_delay(delays)

delaysa list of departure delays in minutes (negative means early)

Returnsthe mean delay, or 0 for an empty list

Rulehandle only the error an empty list really causes

Examples

callaverage_delay([-4, 12, -1, 35])returns10.5

callaverage_delay([0, 30])returns15.0

callaverage_delay([])returns0