[Tutor] Re: Translating to Python [perl --> python]

[Kyle Babich]

How could I do this without cgitb?

Thank you

On Mon, 1 Jul 2002 17:58:52 -0500, "Derrick 'dman' Hudson"
<dman@dman.ddts.net> said:
> On Mon, Jul 01, 2002 at 10:10:02PM +0000, Kyle Babich wrote:
> | Thank you, that's just what I was looking for.  I like it, err...
> | one problem, my server doesn't.  505
> 
> I found 3 problems with Danny's code (must not have been tested :-)),
> and 2 problems with Kyle's code.
> 
> | Results of python -c index.py
> | 
> | Traceback (innermost last):
> |   File "<string>", line 1, in ?
> | NameError: index
> 
> First, "index.py" is a valid python statement only when
>     1)  A variable named 'index' exists
> and
>     2)  that object has a member named 'py'
> 
> What you meant to write was
>     $ python index.py
> 
> Still, that wouldn't help you to debug a CGI script unless you also
> first created the rest of the environment that apache would create for
> the script.
>  
> | Exactly what index.py says:
> 
> | form = cgi.FieldStorage()
> |       c = cgi['c'].value
>   ^
> |       content = 'c'
>   ^
> |               if c == 'abc':
>   ^     ^
> |               content = "abc123"
>   ^^^^^ ^
> 
> That indentation is not valid syntax in python.  That's probbly what
> is causing your 505 error.  A good idea is to look at the web server's
> error log since it will (at least for apache) contain the error
> message.
> 
> Be very consistent in your indentataion or else python will beat you
> with a cluestick :-).
> 
> Rule #1 (this applies to any language, python just enforces it) :
>     Indent blocks of statements at the same indentation level.
>     Indent nested blocks by 1 additional indentation level.
> 
> If you don't indent consistently, then the code is nearly impossible
> to read.  While C, Perl, etc, will let you get away with it (assuming
> the code is correct in the first place and you haven't merely fooled
> yourself), Python won't let you get away with it -- it will be even
> more fooled than you are.
> 
> Rule #2 (this also applies to everything but Makefiles, IMO) :
>     Never use tabs.
>     Always keep your tabstop set at 8.
> 
> Any decent editor can be configured to insert/remove the proper number
> of
> spaces when you press the buttons on your keyboard labeled "tab" and
> "backspace".  Thus the tab character (ASCII 0x09) never needs to be
> stored in the file itself.  Also note that whenever python sees a tab
> character, it treats it as 8 spaces.  If you muck with the size your
> editor displays a tab as, you'll get very confusing syntax errors from
> python because it doesn't see the same thing your eyes see.
> 
> For vim, I recommend these settings :
> 
> 
> " make tabs visible
> set lcs=tab:>-
> set list
> 
> augroup Python
>     au!
>     au FileType python set sts=4 sw=4 et tw=80 fo=croq2 hls
> 
>     " override C preprocessor indenting
>     au FileType python inoremap # X<C-H>#
> 
>     au FileType python set foldmethod=indent
>     " do I want everything collapsed when I open the file?
>     au FileType python set nofoldenable
> 
> augroup END
> 
> 
> Now to correct the bugs in Danny's code :
> 
> 
> #!/usr/bin/env python
> 
> import cgi
> import cgitb
> cgitb.enable()
> 
> 
> # Bug #1:  print the headers first.  Otherwise it is possible to print
> # that "error: content failed" message before the headers are printed.
> print "Content-type: text/html\n\n"
> 
> 
> form = cgi.FieldStorage()
> # Bug #3:  handle the situation where the script was not passed a
> #          parameter 'c'.  Unlike perl/sh, in python accessing
> undefined
> #          variables is an error, not the empty string.
> try :
>     # Bug #2: s/cgi/form/  Danny meant to index the form object, not
>     #         the cgi module.
>     c = form['c'].value
> except KeyError :
>     # What to do if the parameter doesn't exist.  I suppose
>     # considering it to be the empty string is what is desired in this
>     # case.
>     c = ""
> content = 'c'
> if c == 'abc':
>     content = "abc123"
> elif c == 'def':
>     content = "def456"
> else:
>     print "error: content failed\n"
> 
> file = open("text.txt")
> text = file.read()
> file.close()
> 
> print """
> 
> %(content)s
> 
> 
> <br>&nbsp;<br>&nbsp;<br>&nbsp;
> 
> %(text)s
> 
> """ % vars()
> 
> 
> HTH,
> -D
> 
> -- 
> 
> Like a gold ring in a pig's snout
> is a beautiful woman who shows no discretion.
>         Proverbs 11:22
>  
> http://dman.ddts.net/~dman/
>