python - Accessing POST Data from WSGI

35
votes

I can't seem to figure out how to access POST data using WSGI. I tried the example on the wsgi.org website and it didn't work. I'm using Python 3.0 right now. Please don't recommend a WSGI framework as that is not what I'm looking for.

I would like to figure out how to get it into a fieldstorage object.

4
pythonpython-3.xwsgi
FWIW, at this point in time there is still no WSGI specification for Python 3.0, so anything you do will possibly be wasted effort as any final specification update may not be compatible with anyones attempts to implement what it may say for Python 3.0. For WSGI applications you are better off staying with Python 2.X. – Graham Dumpleton
@GrahamDumpleton Not anymore: python.org/dev/peps/pep-3333 (Let's not mislead people who read this a bit later like me - saving their time too) – jeromej
@JermoeJ - He wrote the comment in 2009, and you are replying to it in 2013; don't think he was trying to mislead anyone. :) – Sam

4 Answers

30
votes

Assuming you are trying to get just the POST data into a FieldStorage object:

# env is the environment handed to you by the WSGI server.
# I am removing the query string from the env before passing it to the
# FieldStorage so we only have POST data in there.
post_env = env.copy()
post_env['QUERY_STRING'] = ''
post = cgi.FieldStorage(
    fp=env['wsgi.input'],
    environ=post_env,
    keep_blank_values=True
)
22
votes
body= ''  # b'' for consistency on Python 3.0
try:
    length= int(environ.get('CONTENT_LENGTH', '0'))
except ValueError:
    length= 0
if length!=0:
    body= environ['wsgi.input'].read(length)

Note that WSGI is not yet fully-specified for Python 3.0, and much of the popular WSGI infrastructure has not been converted (or has been 2to3d, but not properly tested). (Even wsgiref.simple_server won't run.) You're in for a rough time doing WSGI on 3.0 today.

4
votes

This worked for me (in Python 3.0):

import urllib.parse

post_input = urllib.parse.parse_qs(environ['wsgi.input'].readline().decode(),True)
-1
votes

I would suggest you look at how some frameworks do it for an example. (I am not recommending any single one, just using them as an example.)

Here is the code from Werkzeug:

http://dev.pocoo.org/projects/werkzeug/browser/werkzeug/wrappers.py#L150

which calls

http://dev.pocoo.org/projects/werkzeug/browser/werkzeug/utils.py#L1420

It's a bit complicated to summarize here, so I won't.