have grown out of favor with the american population but the story is actually more complicated than thatas will be explored in the next section figure - few boy and girl names over time measuring the increase in naming diversity one explanation for the decrease in plots above is that fewer parents are choosing common names for their children this hypothesis can be explored and confirmed in the data one measure is the proportion of births represented by the top most popular nameswhich aggregate and plot by year and sexin [ ]table top pivot_table('prop'rows='year'cols='sex'aggfunc=sumin [ ]table plot(title='sum of table prop by year and sex'yticks=np linspace( )xticks=range( )see figure - for this plot so you can see thatindeedthere appears to be increasing name diversity (decreasing total proportion in the top , another interesting metric is the number of distinct namestaken in order of popularity from highest to lowestin the top of births this number is bit more tricky to compute let' consider just the boy names from in [ ]df boys[boys year = in [ ]df out[ ]int index entries to data columnsus baby names - www it-ebooks info