一分钟运行一次Python函数

Question

I recently started learning Python and I have an application for it where I would like to create a text file that records data every two seconds for a minute, and then begins again with a new file. I have it written where the opened file is formatted for SQL and SQL INSERT queries are being added on.

The trouble I am having is creating the code to actually work properly. The Python itself is working fine for just inserting a new line of SQL to the already opened file, but the output looks like this:

[blank line is here because of the \n]
INSERT INTO table (column 1, column 2) VALUES ('7113', '1337');
INSERT INTO table (column 1, column 2) VALUES ('7113', '1337');

My issue is that I need to get the data so there is no new line at the top and no semicolon at the last row.

This is my source:

from threading import Timer
import time

def start():
    t = Timer(1.0,start)

    foo = "7113"
    bar = "1337"
    date = time.strftime('%Y-%m-%d %H:%M:%S')
    sql = "\nINSERT INTO table (column 1, column 2) VALUES ('%s', '%s');" % (foo, bar)

    query = open(date + ".sql", "a")
    query.write(sql)
    query.close()
    t.start()

start()

Since I'm not the best with language, a simpler version of what I want to do is:

1. Have one function run the first code, spitting out INSERT INTO table (column 1, column 2) VALUES ('7113', '1337'); without the extra line in front but with a semicolon.
2. Have another function run 58 times, adding lines with \\n before the SQL query and the semicolon after.
3. Have the last function run the 60th time, including the \\n but without the semicolon.
4. Close the current file and generate a new text file with the timestamp just for that minute, like 2013-07-09 12-30-00.sql and repeat the process over again for 2013-07-09 12-31-00.sql , and so on.

I imagine there is a lot more after that, like getting a PHP or Python script to read the date and execute it, or I could just have all of them executed and then order the table ascending. However, that can be solved and researched at a later date. I just want to get this working since I've been searching for a few hours now on how to do it and I couldn't find anything helpful. I'm sure the answer is something obvious, though.

Thanks for reading and I hope you guys can help! I've used this website a bunch now for helpful tidbits and it's fantastic. Whoever came up with this needs to be praised a bunch.

Also, if anyone has any useful resources for learning Python (I learned through Codecademy ), I would really appreciate them. This is so much more fun than learning C++.

Answer 1

I solved the problem by having a global counting variable and using if and elif statements. Currently the script is functioning every 500ms with no problem. If anyone wants to see my code, here it is:

Commented version because syntax highlighting here with comments is screwing up for whatever reason.

from threading import Timer
import xml.etree.ElementTree as ET
import urllib
import time

datetime = time.strftime('%Y-%m-%d %H.%M')
filename = datetime + ".sql"
url = "localhost/send.cgi"
interval = 0.5
table_name = "0001"
columns = "(time, foo, bar)"
counting = 0 

def parser():
    t = Timer(interval, parser)
    global counting
    global filename
    query = open(filename, "a")

    if counting == 0:
        date = int(time.time()*1000)
        web = urllib.urlopen(url)
        tree = ET.parse(web)
        root = tree.getroot()
        foo = root[1].text.replace(" ", "")
        bar = root[2].text.replace(" ", "")
        sql = "INSERT INTO %s %s VALUES ('%s', '%s', '%s');" % (table_name, columns, date, foo, bar)
        counting += 1
        query.write(sql)
        print counting
        t.start()
    elif (counting > 0) and (counting < 59):
        date = int(time.time()*1000)
        web = urllib.urlopen(url)
        tree = ET.parse(web)
        root = tree.getroot()
        foo = root[1].text.replace(" ", "")
        bar = root[2].text.replace(" ", "")
        sql = "\nINSERT INTO %s %s VALUES ('%s', '%s', '%s');" % (table_name, columns, date, foo, bar)
        counting += 1
        query.write(sql)
        print counting
        t.start()
    elif counting == 59:
        date = int(time.time()*1000)
        web = urllib.urlopen(url)
        tree = ET.parse(web)
        root = tree.getroot()
        foo = root[1].text.replace(" ", "")
        bar = root[2].text.replace(" ", "")
        sql = "\nINSERT INTO %s %s VALUES ('%s', '%s', '%s')" % (table_name, columns, date, foo, bar)
        counting += 1
        query.write(sql)
        print counting
        t.start()
    elif counting == 60:
        query.close()
        datetime = time.strftime('%Y-%m-%d %H-%M')
        filename = datetime + ".sql"
        counting = 0
        t.start()
parser()

If any improvements can be made, I would love to see them! <3 This code is meant for a certain kind of web server, though. It may require some modifications to work. What the web server does is, when requested, sends a virtual XML file (which is just data, not the file) and this code requests it, interprets it, and shoots it into a .sql file so I can later execute them into a table to something. In the end, the code will grab over ten different columns of data and create the file for an hour, which is 7200 half-seconds.

Enjoy!

EDIT: Yay, apparently the SQL syntax doesn't work. Troubleshooting.