Why doesn't the class attribute update when I change the input value? Tkinter Python 3 - dataframe

Question

I am trying to develop a simple application with tkinter and I want to create a class that performs a search in a dataframe, the search's value it is linked to the information typed in an entry that belongs to another class, however when I run the code, the value of the search is not modified when changing the value of the input. Here the code so far
from tkinter import *
import numpy as np
import pandas as pd
cat = {'N°_Cel': pd.Series(['3007441467', '3164992937', '3212400100', '3258172402', '3169995802'], index= [0, 1, 2, 3, 4]),
'Names': pd.Series(['Jairo Moreno', 'Laura Mesa', 'Camilo Baquero', 'Daniela Smith', 'Ximena Sterling'], index= [0, 1, 2, 3, 4]),
'Adress': pd.Series(['Cll 158 # 96A 25','Cll 132 # 100A 63', 'Cll 158 # 100A 63', 'Cll 148 # 97A 41', 'Cll 172A # 8 20'], index= [0, 1, 2, 3, 4]),
'Schedule': pd.Series(['N.A.', 'Evening.', 'N.A.', 'After 14', 'Morning'], index= [0, 1, 2, 3, 4]),
'Payment': pd.Series(['Credit', 'Cash', 'Credit', 'Credit', 'Cash'], index= [0, 1, 2, 3, 4])}
customer_cat = pd.DataFrame(cat)
class Search_Client():
def __init__(self, info, dataframe, colname):
self.info = info
self.dataframe = dataframe
self.colname = colname
def search(self):
if self.info == '':
result = ''
else:
result = self.dataframe.loc[self.dataframe[self.colname]==self.info]
if result.empty == True:
result = ''
else:
results = result
print(results)
class Order_Document():
def __init__(self, parent):
self.parent = parent
self.parent.geometry('')
self.parent.title('Order document')
self.cellphone_number = StringVar()
Label(self.parent, text= 'Order Document', bg= 'light gray', font= 'Verdana 13', relief= RIDGE).grid(row= 0, column= 0, columnspan= 3) # Se debe centrar al finalizar el diseño de la ventana
Label(self.parent, text= 'Cellphone Number: ', bg = 'white smoke', font= 'Arial 11 bold', justify= 'left').grid(row= 5, column= 0, sticky= 'we')
Entry(self.parent, textvariable= self.cellphone_number, font= 'Arial 11').grid(row=5, column= 1, sticky= 'we')
self.search_client = Search_Client(self.cellphone_number.get(), customer_cat, 'N°_Cel')
Button(self.parent, text= 'Buscar', command= self.search_client.search, bg= 'gold', font= 'Verdana 13').grid(row= 5, column= 3, sticky= 'we')
app = Tk()
ejec = Order_Document(app)
app.mainloop()
I don't know what I could be doing wrong, I hope you can help me.