How can I pass “start date” and “end date” as command line arguments in Python

Question

I am trying to transfer data from one table to another using Python based on date range.

import anprint
import os
import sys
import re
import datetime
from mydb import cursor

try:
    cam_name = sys.argv[1]
    rec_date = sys.argv[2]
except:
    print "Usage: %s cam_name date " % sys.argv[0]
    sys.exit(1)

dbObj = anprint.ExcelDb()

# Get a list of the plates...
tablename = "customer_1.%s_anpr_vega" % cam_name
sql = """SELECT plate, datetime, id FROM %s WHERE DATE(datetime)="%s" """ % (tablename, rec_date)
cursor.execute(sql)
retval = cursor.fetchall()
for values in retval:
    print values
    (vrm, vrm_datetime, record_id) = values
    dbObj.reconcile_plate(cam_name, vrm, vrm_datetime, record_id)

Answer 1

1) It bad paractice:

sql = """SELECT plate, datetime, id FROM %s WHERE DATE(datetime)="%s" """ % (tablename, rec_date)
cursor.execute(sql)

Do below:

sql = """SELECT plate, datetime, id FROM %s WHERE DATE(datetime)=?""" % tablename
cursor.execute(sql, [rec_date])

2) It's simple and not good solution to use sys.argv[n] for get command line arguments like cam_name = sys.argv[1] . Good way is to use argparse for assign command line arguments to script.

3) It's good practice use between operator in sql like this:

sql = "SELECT plate, datetime, id FROM " +tablename+ " WHERE datetime between ? and ?"
    cursor.execute(sql, [start_date, end_date])

Furthermore read it for understanding parameters style SQL query.