cgi python

**Christian Hausknecht** · Oct 13 '05, 03:15 PM

Re: cgi python

Python_it wrote:
[color=blue]
> I going to use the cgi-handler (mod_python):
>
> http://www.modpython.org/live/mod_py.../hand-cgi.html
>
>
> If I test a simply py script it works
>
> code:
> ===========
> print "Content-type: text/html\n"
> print """
> <html>
> <body>
> <h1>TEST</h1>
> </body>
> </html>
> """
> ============
>
> But if I test a py script with cgi comments (import cgi):
>
> Part of the code
> ============
> import cgi
>
> #get HTTP query parameters
> query = cgi.FieldStorag e()
>
> #Get the selected year and month
> selectedYear = int(query["year"].value)
> selectedMonth = int(query["x"].value) + 1
>
> #Get the monthly revenue
> monthlyRevenue = float(query["value"].value)
> ============
>
> I get the following error:
>
> errormessage:
> =============== ===========
> Mod_python error: "PythonHand ler mod_python.cgih andler"
>
> Traceback (most recent call last):
>
> File "C:\Program
> Files\Python24\ Lib\site-packages\mod_py thon\apache.py" , line 299, in
> HandlerDispatch
> result = object(req)
>
> File "C:\Program
> Files\Python24\ Lib\site-packages\mod_py thon\cgihandler .py", line 96, in
> handler
> imp.load_module (module_name, fd, path, desc)
>
> File "C:/Program Files/Apache
> Group/Apache2/htdocs/clue/modules/templates\click pie.py", line 9, in ?
> selectedYear = int(query["year"].value)
>
> File "C:\Program Files\Python24\ Lib\cgi.py", line 559, in __getitem__
> raise KeyError, key
>
> KeyError: 'year'
>
>
> Who can help me?[/color]
There is no Parameter 'year' in the Format-String sent by the Webserver!
You can test it like this:
if(query.has_ke y("yaer")):
xyz = query["year"].value

If you want to get a Parameter called 'year', you must call the cgi-Script
like this:

http://host/path-to-cgi-dir/script.py?year=2005

Another method is, to use a form in the calling html-Page and put a hidden
value into it.

Ciao,
Christian

**Paul Boddie** · Oct 13 '05, 03:25 PM

Re: cgi python

Python_it wrote:[color=blue]
> I going to use the cgi-handler (mod_python):
>
> http://www.modpython.org/live/mod_py.../hand-cgi.html
>
> If I test a simply py script it works[/color]

You don't say how you test it, but I imagine that you just point your
browser to the location where the program is published, without
specifying any query parameters - see below for the significance of
this.

[...]
[color=blue]
> But if I test a py script with cgi comments (import cgi):
>
> Part of the code
> ============
> import cgi
>
> #get HTTP query parameters
> query = cgi.FieldStorag e()
>
> #Get the selected year and month
> selectedYear = int(query["year"].value)[/color]

[...]
[color=blue]
> KeyError: 'year'[/color]

The problem is that if you point your browser to this new program and
don't specify query parameters (eg. ?year=2005&x=10 &value=5000 on the
end of the URL) then attempting to get the "year" parameter from the
query object will fail because the parameter doesn't exist - you didn't
specify it.

What you should do is to test for its presence first, just like you
would with a normal Python dictionary, and I believe that the query
object supports the has_key method:

if query.has_key(" year"):
selectedYear = int(query["year"].value)

A more comprehensive alternative, given that the "year" parameter may
not be a number, is to catch any exceptions raised when you try and get
the parameter's value:

try:
selectedYear = int(query["year"].value)
except KeyError:
Do something here about the missing parameter.
except ValueError:
Do something here about a non-integer parameter.

Testing Web applications can be hard, but the traceback tells you
everything you need to know here.

Paul

**Fredrik Lundh** · Oct 13 '05, 03:55 PM

Re: cgi python

Paul Boddie wrote:
[color=blue]
> Testing Web applications can be hard, but the traceback tells you
> everything you need to know here.[/color]

especially if you make sure to use the cgitb module:

cgitb — Traceback manager for CGI scripts

http://docs.python.org/lib/module-cgitb.html

This module is no longer part of the Python standard library. It was removed in Python 3.13 after being deprecated in Python 3.11. The removal was decided in PEP 594. A fork of the module on PyPI c...

while developing/debugging.

</F>

cgi python

cgi python

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