Paul's Programming Notes

Virtualenvwrapper Basics

This video does a good job of describing the basics of Virtualenvwrapper: https://www.youtube.com/watch?v=thHNYVrY0lU

You’ll need to have used virtualenv to appreciate this.

Basically, you create virtual environments with mkvirtualenv and they’re stored in a central location. When you want to switch to your virtual environment, you use the workon command.

You can also create a postactivate script that loads environmental variables when you switch to your virtual environment.

Note: There is also a module called Pew that seems to have a simpler installation process: https://github.com/berdario/pew

Meetup API address_1_error

I was getting this error while using the POST /venues method of the meetup API.

The error seems to happen when you duplicate the address of another venue. I was able to add the venue, but when I tried to add it a second time - I would get this error.

I ended up getting the list of venues and trying to find a match first.

Eventbrite "Application Key Error"

The error message looks like this:

{u'status': {u'http_code': 200}, u'contents': {u'error': {u'error_type': u'Application Key Error', u'error_message': u'Please provide your Application Key in the URL as "?app_key=<APP_KEY>".'}}}

After a few hours of trying to get past the Eventbrite API’s “Application Key Error”. I finally figured out that I needed to switch my request URL from:

"https://developer.eventbrite.com/json/event_new"

to:

"https://www.eventbrite.com/json/event_new"

None Can Be A Key In Python Dicts

None is hashable, so it works as a dictionary key like any other immutable value.

>>> my_dict = {None: "value"}
>>> my_dict[None]
'value'

This is handy when you’re grouping rows by a column that can be NULL, because the NULL group gets None for its key and you don’t have to invent a sentinel value to stand in for it.