NoneType error when converting tuple to list

I am trying to select a row from a sqlite database. Make a number of changes then commit them back to the sqlite database as well as a mysql database.

The way I am trying to do it is by converting the tuple retrieved by the SELECT query into a list to make the changes.

key = 27361
c.execute("SELECT * FROM employees WHERE key = ?", (key,))
employeeTuple = c.fetchone()
employeeList = list(employeeTuple)

I am getting an error:

TypeError: 'NoneType' object is not iterable