Car Shopping Problem¶
After accidentally leaving an ice chest of fish and shrimp in your car for a week while you were on vacation, you’re now
in the market for a new vehicle 
. Your insurance didn’t cover the loss, so you want to make sure you get a good deal on
your new car.
Given a Series of car asking_prices and another Series of car fair_prices, determine which cars for
sale are a good deal. In other words, identify cars whose asking price is less than their fair price.
import numpy as np
import pandas as pd
asking_prices = pd.Series([5000, 7600, 9000, 8500, 7000], index=['civic', 'civic', 'camry', 'mustang', 'mustang'])
fair_prices = pd.Series([5500, 7500, 7500], index=['civic', 'mustang', 'camry'])
print(asking_prices)
# civic 5000
# civic 7600
# camry 9000
# mustang 8500
# mustang 7000
# dtype: int64
print(fair_prices)
# civic 5500
# mustang 7500
# camry 7500
# dtype: int64
The result should be a list of integer indices corresponding to the good deals in asking_prices.