Python variable in a sqlite query

so Im looking for the way to be able to compare what is in a python with something in a SQLite query.For example:

num = input ("enter a number")
cur.execute("SELECT a.Name,a.Number FROM Ads a WHERE a.Number =  (num)") //part where it doesnt work
    row = cur.fetchone()
    while row:
        print(row) 
        row = cur.fetchone()

This doesnt work. I dont know how to be able to compare content of a python variable with data in a SQLite database via a SQlite query.

Thank you