Good day
how do i use the .unique to retrieve data
how do i calculate life expentancy
The .unique() function is applied on a Pandas Series Object i.e on one Column of a dataframe at a time, it is used to extract the unque values from a single column
Follow the link to get better details about unique()
The overall life expectancy of the world is,
life expectancy per country * Population of the country/Total Population of the World