Unknown format code ‘f’ for object of type ‘str’- Folium

The f format code in “{:.0f}”.format(Number) for the Python string formatter requires a floating number, and yet you’re passing to it the variable Number, which is derived from dsa[‘Number’], a string value from the dataframe. You should convert Number to a floating number before passing it to the formatter with “{:.0f}”.format(float(Number)) instead.