Initialization

Assuming you have completed the Python Tracker Setup for your Python project, you are now ready to initialize the Python Tracker.

note

Version 0.13.0 introduces the Snowplow interface, making tracker creation and management simpler, for versions <0.13.0 go to Importing the module

The Snowplow Class

The Snowplow class contains static methods to help manage Tracker objects.

Import the Snowplow class along with the required configuration objects:

from snowplow_tracker import Snowplow, EmitterConfiguration, Subject, TrackerConfiguration

The simplest tracker configuration can be instantiated with the create_tracker() method as follows:

Snowplow.create_tracker(namespace='ns', endpoint='collector.example.com')

This creates a Tracker and Emitter with default settings, with events logged to collector.example.com.

You can access a tracker in the following way:

Snowplow.get_tracker('ns')

The Snowplow class can be used to initialize trackers using the following properties:

Argument Name	Description	Required?	Default
namespace	The name of the tracker	Yes
endpoint	The collector URL events are sent to	Yes
method	The method to use: “get” or “post”	No	post
emitter_config	The emitter configuration object	No	EmitterConfiguration()
app_id	The application ID	No	None
subject	The user being tracked	No	subject.Subject()
tracker_config	The tracker configuration object	No	TrackerConfiguration()

Importing the module

Require the Python Tracker's module into your Python code like so:

from snowplow_tracker import Tracker, Emitter, Subject

That's it - you are now ready to initialize a tracker instance.

Creating a tracker

The simplest tracker initialization only requires you to provide the Emitter's endpoint to which the tracker will log events:

e = Emitter("collector.example.com")
t = Tracker(e)

The tracker parameters are:

Argument Name	Description	Required?	Default
emitters	The emitter(s) to which events are sent	Yes
subject	The user being tracked	No	subject.Subject()
namespace	The name of the tracker instance	No	None
app_id	The application ID	No	None
encode_base64	Whether to enable base 64 encoding	No	True
json_encoder	Custom JSON serializer	No	None

Here is a more complete example in which every tracker parameter is set:

e = Emitter("collector.example.com")
s = Subject().set_platform("srv")

tracker = Tracker( e, 
                   subject=s, 
                   namespace="cf", 
                   app_id="aid", 
                   encode_base64=False,
                   json_encoder=my_custom_encoder)

emitters

This can be a single emitter or an array containing at least one emitter. The tracker will send events to these emitters, which will in turn send them to a collector.

e1 = Emitter("mycollector.com")
e2 = Emitter("myothercollector.com", port=8080)
tracker = Tracker([e1, e2])

subject

The user which the Tracker will track. This should be an instance of the Subject class. You don't need to set this during Tracker construction; in this case the tracker will set a default subject, which you can also change using the Tracker.set_subject method afterwards.

**New in v0.9.0

Since version 0.9.0, you can also set a different subject per event instead of having to change the default subject. You can read more about it in the Subject documentation here.

namespace

If provided, the namespace argument will be attached to every event fired by the new tracker. This allows you to later identify which tracker fired which event if you have multiple trackers running.

app_id

The app_id argument lets you set the application ID to any string.

encode_base64

By default, unstructured events and custom contexts are encoded into Base64 to ensure that no data is lost or corrupted. You can turn encoding on or off using the Boolean encode_base64 argument.

json_encoder - (new in v0.9.0)

This parameter allows you to customize the JSON encoder used to serialize objects added to the payload. For example:

from json.encoder import JSONEncoder
def complex_encoder(c):
    if isinstance(c,complex):
        return [c.real, c.imag]
    return JSONEncoder.default(c)

t = Tracker(e, json_encoder=complex_encoder)