Chicago (ORD)ata

This library is for accessing Chicago related data via Python. I'd prefer to focus on web APIs but I'm gonna go where the data is.

CTA Traintracker

To start, I'm implementing Train Tracker API. Below is a cursory usage example.

To start up, just instantiate an instance of the Train class to initialize the connection to the API.

>>> import ordat.cta as cta
>>> train = cta.Train(key='YOURKEYHERE')

Get Arrivals by mapid

>>> train.arrivals(mapid=40380)
[Blue Line/Clark/Lake run 139 to O'Hare at 03:00:00, Blue Line/Clark/Lake run 225 to Forest Park at 03:06:52]

Advanced Mode: Find All Scheduled/Active Runs

>>> # get arrivals for every station in the system
>>> all_arrivals = reduce(lambda a1,a2: a1+a2, [station.arrivals() for station in cta.Station.all])
>>> # get the run numbers of every active train in the system at the current time
>>> run_nums = set([arrival.run_number for arrival in all_arrivals])
>>> len(run_nums)
16

This was run late at night, so it found far less than normal!

Find Current Train Locations

import ordat.cta as cta
train = cta.Train(key='YOURKEYHERE')
tr = cta.panopticon.Tracker()
for rn,lat,lon in tr.step() :
  print rn, lat, lon

This can take a bit to pick up the locations, so run the last two lines a couple times and wait in between.

Station Search, Station Arrivals, Stop Arrivals

>>> # Find a station, and then check its arrivals
>>> cta.Station.find('Clark/Lake')[0].arrivals()
[Blue Line/Clark/Lake run 139 to O'Hare at 03:00:00, Blue Line/Clark/Lake run 225 to Forest Park at 03:05:53]
>>> # Check what lines a station services
>>> cta.Station.find('Clark/Lake')[0].lines
[Pink Line, Blue Line, Purple Express Line, Orange Line, Brown Line, Green Line]
>>> cl_stops = cta.Station.find('Clark/Lake')[0].stops
>>> cl_stops
[E-bound Stop Clark/Lake (Inner Loop) at Station Clark/Lake, W-bound Stop Clark/Lake (Outer Loop) at Station Clark/Lake, S-bound Stop Clark/Lake (Forest Pk-bound) at Station Clark/Lake, N-bound Stop Clark/Lake (O'Hare-bound) at Station Clark/Lake]
>>> cl_stops[-1].arrivals()
[Blue Line/Clark/Lake run 139 to O'Hare at 03:00:00]

I intend to make the data more well formed and parsed, validated etc later. It implements a thin little caching layer to conserve API usage for requests for the same information placed in quick succession.

This is a quick wrapper around http://www.transitchicago.com/assets/1/developer_center/cta_Train_Tracker_API_documentation_v1_2.pdf

To add:

• Finding closest stations by lat/long, line, name, etc
• inbuilt code for acquiring data about stop-to-stop transit timings
• ability to understand delays, scheduled stops, faults in the system
• Unit testing for all of above
• Relate responses and requests on the arrivals API to my object hierarchy
• Color codes on lines
• Directionality of lines
• Determine 'next' stops for each stop (platform)

Dependencies

• git://github.com/martinblech/xmltodict.git
• Everything in requirements.txt

Tests

PYTHONPATH=../xmltodict:~/pyenvs/cta/lib/python2.7/site-packages/ nosetests -vv tests

The above is just an example, I'm not sure why virtualenv isn't picking up the requests module just by sourcing activate.