How to convert datatype of the columns?

Question

I picked up part of the code from here and expanded a bit. However, I am not able to convert the datatypes of Basket & Count columns for further processing. for e.g., Basket and Count columns are int64, I would like to change them to float64.

import ipywidgets as widgets
from IPython.display import display, clear_output

# creating a DataFrame
df = pd.DataFrame({'Basket': [1, 2, 3],
                  'Name': ['Apple', 'Orange', 
                           'Count'], 
                  'id': [111, 222, 
                         333]})

vardict = df.columns
select_variable = widgets.Dropdown(
   options=vardict,
   value=vardict[0],
   description='Select variable:',
   disabled=False,
   button_style=''
)
def get_and_plot(b):
   clear_output
   s = select_variable.value
   col_dtype = df[s].dtypes
   print(col_dtype)

 

display(select_variable)
select_variable.observe(get_and_plot, names='value')

Thanks in advance.