Yet another web.py name collision

I'm trying to make a simple Hello World web page in Python 3.7.4 and web.py 0.40-dev1 (which is supposed to be compatible) and I'm running into

AttributeError: module 'web' has no attribute 'applications'

error. I've googled enough to know that is a name collision, but for the love of God I can't trace it.

Here's the full code:

import web

urls = (
    '/', 'index'
)

application = web.applications(urls, globals())

class index:
    def GET(self):
        greeting = 'Hello world'
        return greeting

if __name__ == "__main__":
    application.run

And here's the full Python interpreter output:

Traceback (most recent call last):
  File "bin\app.py", line 7, in <module>
    application = web.applications(urls, globals())
AttributeError: module 'web' has no attribute 'applications'

Solution

Because of you I just install web.py to test your code. It seems there is no applications in the web.py. If your want to check it just try the below example.

>>> import web
>>> 
>>> `applications` in dir(web)
False
>>> `application` in dir(web)
True

So is should be web.application. Your first problem be solved, when you run it you'll get another error RuntimeError: generator raised StopIteration. That problem is solved in “RuntimeError: generator raised StopIteration” every time I try to run app question. It occurs because of python 3.7.* versions. There is something wrong with 0.40-dev1 version. You have two opetions.

Remove the 0.40-dev1 version and install the stable version from there master branch. Just uninstall by using this command pip uninstall web.py==0.40-dev1 and run this command pip install -e git+https://github.com/webpy/webpy.git#egg=webpy. This will install the latest version from master branch. (This is worked for me)
Next one is update the utils.py in this way. Find it from from Python\Python37\Lib\site-packages\web\utils.py (I try it from windows) and find the line 526. Then you'll see something like thisyield next(seq) and surround it with try-catch statement in this way. (Not Recommended, instead of that make your own version by fork the relevant branch)

def take(seq, n):
    for i in range(n):
        # yield next(seq)
        try:
            yield next(seq)
        except StopIteration:
            return

This will solved your problem. I added some extra context here because I want to see the output. I don't know much about this change, just took it from “RuntimeError: generator raised StopIteration” every time I try to run app question.