Dropdown app to select CSV file - updated plot won't appear from default plot

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Thank you for the help! You were right, I was not able to update the range from the default “fruit file”. I reformatted my code using another discourse example and have posted the working code below.

from bokeh.io import curdoc
from bokeh.plotting import figure
from bokeh.models import ColumnDataSource, Select, FactorRange
from bokeh.layouts import column

import pandas as pd
import numpy as np

curdoc().clear()

#on dropdown callback I do the following: change xrange and update source date
def callback(attr, old, new):
    if menu.value == 'soda': 
        df = pd.read_csv('https://raw.githubusercontent.com/chanson24/PracticeCSVFiles/main/SodaFile.csv?_sm_au_=iVVPr4kSSLkrP8P2pGsWvKttvN1NG')
    else:
        df = pd.read_csv('https://raw.githubusercontent.com/chanson24/PracticeCSVFiles/main/FruitFile.csv?_sm_au_=iVVPr4kSSLkrP8P2pGsWvKttvN1NG')
    df = pd.DataFrame(df.reset_index(drop = True))
    
    global X, Y, x_name, y_name    
    x_name = list(df.columns)[0]
    y_name = list(df.columns)[1]
    
    X = list(df[x_name])
    Y = list(df[y_name])
    
    new_data = dict()
    new_data['my_labels'] = X
    new_data['my_values'] = Y
    plot.x_range.factors = list(X)
    
    source1.data= new_data

    print("callback initiated")

    
#empty values of CDS - but we can populate it from here using the CDS method
source1 = ColumnDataSource(data = dict(my_labels=[], my_values = []))
plot = figure(x_range=[], title="example dropdown")
plot.vbar(x='my_labels', top='my_values', width=0.9, source=source1)
plot.y_range.start = 0


menu = Select(options=['fruit', 'soda'], value='fruit', title='Select object')
menu.on_change('value', callback)

layout = column(menu, plot)
curdoc().add_root(layout)
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