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Name: [011] John Montgomery
Member: 126 months
Authored: 21 videos
Description: I'm a C/C++, Java and Python programmer living in Hove, UK. ...

Writing a Python CGI Wiki - displaying an edit form [ID:664] (5/6)

in series: Introduction to Python web-programming: CGI

(Showmedo is undergoing major changes. To report any problems viewing the videos please email us and include browser and OS specifics. Cheers - Kyran.)

In this episode I modify our Python CGI wiki script to display an edit form when we try to view a page that does not currently exist. I also add an edit link, so that existing pages can be edited.

The common Python idiom of using a dictionary to emulate a switch/case statement is used to select between viewing and editing a page.

At this stage we have something that is beginning to resemble a proper wiki, but is not yet fully functional. In the next episode we will add the ability to save an edits we make to pages.


import cgi
import cgitb; cgitb.enable()
import os
import urllib


def url(**kw):
    params=["%s=%s" % (key,urllib.quote_plus(value)) for key,value in kw.items()]
    return "?" + "&".join(params)

def page_file_name(page):
    file_name="%s.txt" % urllib.quote_plus(page)
    return os.path.join(CONTENTS_DIR,file_name)

def page_contents(page):
    if not os.path.exists(file_name):
        return None
    return file(file_name).read()

def page_header(title):
    print "Content-Type: text/html"
    print "<!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' ''>"
    print "<html xmlns=''>"
    print "<head>"
    print "<title>%s</title>" % cgi.escape(title)
    print "</head>"
    print "<body>"

def page_footer(page=None):
	print "<div class='footer_links'>"
	if page is not None:
		print "[<a href='%s'>%s</a>]" % (cgi.escape(url(page=page,action='edit')),'edit')
	print "</div>"
	print "</body>"
	print "</html>"

def view_page(page,params):
    if contents is None:
    print "<h1>%s</h1>" % cgi.escape(page)
    print "<div class='contents'>"
    print cgi.escape(contents)
    print "</div>"

def edit_page(page,params):
    if contents is None:

    print "<h1>%s: %s</h1>" % (title,cgi.escape(page))
    print "<div class='contents'>"
    print "<form method='post'>"
    print "<input type='hidden' name='page' value='%s' />" % cgi.escape(page)
    print "<input type='hidden' name='action' value='save' />"
    print "<textarea name='contents' rows='20' cols='80'>%s</textarea>"  % cgi.escape(contents)
    print "<div><input type='submit' value='Save' /></div>"
    print "</form>"
    print "</div>"

views = { 'view': view_page, 'edit': edit_page }

def execute(params):


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Great videos with good sound quality. Nice work...

very nice example. keep making videos please...

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At Showmedo we believe the community can play a vital role here and also say thanks for the tools and software that make our lives easier. If you have a piece of software you love or a programming langugage you are enthusiastic about, why not make a screencast showing others how to use it? All the stuff you wish you'd been told, the tips, tricks, insights that would have saved you time and frustration.

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Kudos and Thanks for John

The 'Hello World' Applet - Part 1

Thanks very helpful!


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