Delete duplicate contacts and contacts with more or less than 13 digits

duplicated_contacts.py

import pandas as pd

contacts = pd.read_csv("contacts.csv")

contacts.drop_duplicates(subset=['Numero di telefono']) # name of the column that identifies the telephone number

# clears numbers that have more than 13 digits
index_to_drop = contacts[contacts['Numero di telefono'].map(len) != 13].index
contacts.drop(index_to_drop, inplace=True)

# save in a new csv
contacts.to_csv('contacts_new.csv', index = False)