Search through SQL table and delete row if cell already exists

I have a table using SQL Lite with Python. The size of the table always has 3 columns and could have many rows. Each of the cells are strings. Here is example table:

serial_num   date_measured  status
1234A        1-1-2015       passed
4321B        6-21-2015      failed
1423C        12-25-2015     passed

......

My program prompts me for a serial number. This is saved as a variable called serialNum. How can I delete (or overwrite) an entire row if serialNum equals any of the strings in the serial_num column in my table?

I've seen many examples on how to delete (or overwrite) a row in a table if I know all the values in each cell of that row, but my trouble is that the only cell that could ever be the same in each row would be the serial number. I need to so a search through the serial_number column and if any string in that column equals the current value of my serialNum variable, I need to delete (or overwrite) that row.

import sqlite3
conn = sqlite3.connect('example.db')
c = conn.cursor()

c.execute('''CREATE TABLE test (serial_num text,  date_measured text, status text)''')
c.execute("INSERT INTO test VALUES ('1234A', '1-1-2015', 'passed')")
c.execute("INSERT INTO test VALUES ('4321B', '6-21-2015', 'failed')")
c.execute("INSERT INTO test VALUES ('1423C', '12-25-2015', 'passed')")
conn.commit()

Does anyone know a simple way to do this? I've seen others say that an ID must be used or a temporary table, but I would hope there might be an easier way to accomplish my task. Any advice would be great.