How to check & change datatype of a column of panda dataframe using combobox in jupyter notebook?

Question

I would like to convert the data type of a column but using ipython wigets:

1. Combobox1 will display all columns of the data frame.
2. Disabled Text1 box will show the existing datatype of the column selected at step 1.
3. Next Combobox2 will give options like, {'int', 'float', 'datetime', 'object'}
4. Text2 box will show something like: df['customerID'].dtypes = String
5. Output in Text2 must be stored in a variable for future programming.
6. Button to execute data type conversion.

Code that I referred(but not been able to customize completely):

# Common Imports for Widgets
from ipywidgets import interact, interactive, fixed, interact_manual
import ipywidgets as widgets

df = pd.read_csv('TelcomCustomer-Churn.csv', index_col = 0)

foo = df.columns

# Function to apply to drop box object
def bar(x):
    print(x,'\n') # Whole object
    print(x.new,'\n') # New value

# creation of a widget dropdown object
box1 = widgets.Dropdown(
    options=foo, # Object to iterate over
    description='Column Name:', 
    value=foo[1], # Default value selection
    rows=len(foo), # The number of rows to display when showing the box
    interactive=True, 
);
#text box
text = widgets.Text(
    value='last',
    placeholder='datatype',
    description='String:',
    disabled=True
)

def callback(wdgt):
    with output:
        clear_output
        display(wdgt.value)

text.on_submit(callback)
# Drop box of k,v like pairs 
box2 = widgets.Dropdown(
    options=[('Object', 1), ('float', 2), ('int', 3), ('datetime', 4)],
    value=1,
    description='datatypes:',
)

# Button to click
select_button = widgets.Button(
    description='Convert Datatype',
    # missing action to be perfomed
    disabled=False
)

# Event Handlers
box1.observe(bar,names='value')
text.observe(bar,names='value')
box2.observe(bar,names='value')
select_button.on_click(get_user_selection)
[enter image description here][1]
ui = widgets.HBox([box1,text,box2,select_button]) 

# display the UI
display(ui)

Code Output