Question $1\mathrm{.}1(12\%$ credit$)$

It looks like the departure and arrival in flights were read in as floating$-$point numbers. Write two functions, extract$\_$hour and extract$\_$mins that converts military time to hours and minutes, respectively. Hint: You may want to use modular arithmetic and integer division. Keep in mind that the data has not been cleaned and you need to check whether the extracted values are valid. Replace all the invalid values with NaN. The documentation for pandas.Series.where provided here should be helpful.