population = {"Shanghai":17.8, "Istanbul":13.3, "Karachi":13.0, "Mumbai":12.5}
#Consider the following when creating a dictionary
# 1. Must be inside {}
# 2. Have two parts in an item
# Key - e.g. Istanbul and Value - e.g. 13.3
# 3. There must be a colon ":" between the key and the value
# 4. Item must be seperated by commas ","
# 3. Any immutable type can be used as keys (not only integers like in lists)