I have a dataframe with a column "C" which contains address information. How can I single out the number of unique cities? In the example below it would be London, Paris and Barcelona?
A B C
Grey no 84 Sussex Gardens Westminster Borough London W2 1UH United Kingdom
Red yes 71 Rue de Charonne 11th arr 75011 Paris France
Blue yes Diputaci 262 264 Eixample 08007 Barcelona Spain
A B C
Grey no 84 Sussex Gardens Westminster Borough London W2 1UH United Kingdom
Red yes 71 Rue de Charonne 11th arr 75011 Paris France
Blue yes Diputaci 262 264 Eixample 08007 Barcelona Spain