# 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.