Question

I'm a Java developer currently trying to write my own Python library. I have most of the functionality (that I want) down, I'm just having trouble with some Python syntax intricacies. I thought I had working code but when I tried an example I got this error:

/usr/local/Cellar/python3/3.4.3/Frameworks/Python.framework/Versions/3.4/bin/python3.4 /Users/willkara/Development/GitHub/SakaiPy/Examples/Example.py
Traceback (most recent call last):
  File "/Users/willkara/Development/GitHub/SakaiPy/Examples/Example.py", line 14, in <module>
    site = Sak.getSakaiSite('1e420647-1dce-4dbb-a789-9dfae3ccc8d8')
  File "/Users/willkara/Development/GitHub/SakaiPy/SakaiPy/SakaiPy.py", line 28, in getSakaiSite
    return SakaiSite.SakaiSite(self, self.requester, siteid)
TypeError: __init__() takes 3 positional arguments but 4 were given

My goal is to have this base object SakaiPy that is the main class for the library that handles most of the high level logic.

I want user to be able to do this at the end after user imports the project.

SakaiPyObject = SakaiPy(connectioninfo)

site = SakaiPyObject.getSakaiSite('site id goes here')

announcements = site.getAnnouncements()

I have most of classes & functions setup, I just am having trouble with some of the differences between Python and Java in how they handle constructors/methods/imports.

This is my code for the SakaiPy object:

#!/usr/bin/python
# -*- coding: utf-8 -*-
import requests

from SakaiPy import RequestHandler
from SakaiPy.SakaiTools import SakaiSite

loginURL = "/direct/session?_username={0}&_password={1}"

session = requests.Session()


class SakaiPy(object):
    def __init__(self, connectioninfo):
        """Generate the session cookie"""

        self.baseURL = connectioninfo['baseURL']

        # Generate a session cookie & store it in the requesting session
        session.post(self.baseURL + loginURL.format(
            connectioninfo['username'],
            connectioninfo['password']
        ))

        self.requester = RequestHandler.RequestHandler(session, self.baseURL)

    def getSakaiSite(self, siteid):
        return SakaiSite.SakaiSite(self, self.requester, siteid)

For the RequestHandler object:

#!/usr/bin/python
# -*- coding: utf-8 -*-


class RequestHandler(object):
    def __init__(self, session, url):
        self.baseUrl = url
        self.session = session

    """This class handles the login/cookie mechanisms and request generation."""

    def executeRequest(self, url):
        """Returns the JSON response from the specified URL."""

        response = self.session.get(self.baseURL + url)

        """If it is a good response, then return the content in json form for the Sakai Object.
           If it is a bad response, raise an exception.
        """
        if response.status_code == 200:
            return response.json()
        else:
            response.raise_for_status()

And for the SakaiSite object:

#!/usr/bin/python
# -*- coding: utf-8 -*-



class SakaiSite(object):
    def __init__(self, rq, siteid):
        self.requester = rq
        self.siteid = siteid

    def getMemership(self):
        return self.requester.executeRequest('/direct/membership/site/{0}.json'.format(self.siteid))

    def getRoster(self):
        return self.requester.executeRequest('/direct/roster/site/{0}.json'.format(self.siteid))

    def getGradebook(self):
        return self.requester.executeRequest('/direct/gradebook/site/{0}.json'.format(self.siteid))

    def getNews(self):
        return self.requester.executeRequest('/direct/news/site/{0}.json'.format(self.siteid))

    def getCalendar(self):
        return self.requester.executeRequest('/direct/calendar/site/{0}.json'.format(self.siteid))

    def getAnnouncements(self):
        return self.requester.executeRequest('/direct/announcement/site/{0}.json'.format(self.siteid))

    def getForums(self):
        return self.requester.executeRequest('/direct/forums/site/{0}.json'.format(self.siteid))

    def getContents(self):
        return self.requester.executeRequest('/direct/content/site/{0}.json'.format(self.siteid))

and finally, here is the demo code I have:

#!/usr/bin/python
# -*- coding: utf-8 -*-
from SakaiPy import SakaiPy

"""Say I want to get a list of all of the Calendars I have for a specific site. I'll write all the code first then explain each part."""

authInfo = {}
authInfo['baseURL'] = "https://sakai.rutgers.edu"

authInfo['username'] = "username"
authInfo['password'] = "password"

Sak = SakaiPy.SakaiPy(authInfo)
site = Sak.getSakaiSite('siteid')

site.getAnnouncements()

Answer 1

self is passed implicitly to constructors

so

return SakaiSite.SakaiSite(self, self.requester, siteid)

is really

return SakaiSite.SakaiSite(self,self, self.requester, siteid)

instead you should ommit the self argument as it will be passed implicitly

return SakaiSite.SakaiSite( self.requester, siteid)

Python mismatch with given arguments in method

1 个答案: