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January 27th, 2004, 11:21 AM

lucas

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Loops

OK i've written my program, but instead of having it exit i want it to rune again and again for an infinite number of times, or until someone types quit or ext etc. How would I go about this, im guessing it involves loops but iv tried a few things and they dont work.

January 27th, 2004, 11:31 AM

netytan

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What you're looking for here is a while True loop, luckily not hard

check it out!

Code:

while True:
    ...
    code here
    ...
    if typed == 'quit':
        ...
        break
        ...

Mark.

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January 27th, 2004, 12:06 PM

lucas

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OK this is the code:

Code:

#!/usr/bin/env python
while true:
import sys, time, os, urllib
choice = raw_input('Type (news) for news or (web)to visit the website (forum) to go to the forum.')
if choice == 'news':
    for each in range(5):
	sys.stdout.write('[' + '=' * each + ']\r')
	time.sleep(0.2)
    page = urllib.urlopen('http://www.geocities.com/hlh_halo/news.txt').read()
    file('news.txt', 'w').write(page)
    os.system('news.txt')
    print
elif choice == 'web':
    for each in range(5):
	sys.stdout.write('[' + '=' * each + ']\r')
	time.sleep(0.2)
    os.system('explorer http://www.geocities.com/hlh_halo')
    print
elif choice == 'forum':
    for each in range(5):
	sys.stdout.write('[' + '=' * each + ']\r')
	time.sleep(0.2)
    os.system('explorer http://lucas900.proboards18.com/index.cgi')
    print 
if typed == 'quit':
    break

and the error message I get about the command 'import' at the top is that an indent was expected. What are indents and how should I fix this problem?
Many thanks.

Last edited by netytan : January 27th, 2004 at 12:11 PM.

January 27th, 2004, 12:16 PM

netytan

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Indents are very important to Python, since there used to denote where blocks start and finish! Definatly dont forget to indent code of you're programs jsut wont work

Soooo.... you're program should end up something like this (untested).

Code:

#!/usr/bin/env python

import sys, time, os, urllib

while True:
	choice = raw_input('Type (news) for news, (web) to visit the website, (forum) to go to the forum or (quit) to quit.')
	if choice == 'news':
		for each in range(5):
			sys.stdout.write('[' + '=' * each + ']\r')
			time.sleep(0.2)
			page = urllib.urlopen('http://www.geocities.com/hlh_halo/news.txt').read()
			file('news.txt', 'w').write(page)
			os.system('news.txt')
			print
	elif choice == 'web':
		for each in range(5):
			sys.stdout.write('[' + '=' * each + ']\r')
			time.sleep(0.2)
			os.system('explorer http://www.geocities.com/hlh_halo')
			print
	elif choice == 'forum':
		for each in range(5):
			sys.stdout.write('[' + '=' * each + ']\r')
			time.sleep(0.2)
			os.system('explorer http://lucas900.proboards18.com/index.cgi')
			print 
	elif choice == 'quit':
		break

Note: don't import inside loops, this can cause major preformance problems on occasion.

Mark.

Last edited by netytan : January 27th, 2004 at 12:18 PM.

January 27th, 2004, 12:25 PM

Strike

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Quote:

Originally posted by netytan
Note: don't import inside loops, this can cause major preformance problems on occasion.

Meta-note: I'm pretty sure this isn't true. Not at my machine right now but I can check it out later on and respond with a definite answer.

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January 27th, 2004, 12:46 PM

lucas

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Iv got it workin, tnx all.

January 27th, 2004, 01:45 PM

netytan

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Quote:

Originally posted by Strike
Meta-note: I'm pretty sure this isn't true. Not at my machine right now but I can check it out later on and respond with a definite answer.

Python is optomized so it doesn't import the same module more than once - you have to call reload(name) to reload a module - but i've read a number of articles on improving preformance and this has come up more than once.

This may have been fixed, but since i havn't heard anything i'd assume it hasnt.

so make of it what you will Strike

, just not the best idea! and what would be the point anyway?

Mark.