EventSource¶

class ctapipe.io.eventsource.EventSource(input_url=traitlets.Undefined, config=None, parent=None, **kwargs)[source]¶

Bases: ctapipe.core.component.Component

Parent class for EventSources.

EventSources read input files and generate ArrayEventContainer instances when iterated over.

A new EventSource should be created for each type of event file read into ctapipe, e.g. sim_telarray files are read by the SimTelEventSource.

EventSource provides a common high-level interface for accessing event information from different data sources (simulation or different camera file formats). Creating an EventSource for a new file format or other event source ensures that data can be accessed in a common way, irregardless of the file format or data origin.

EventSource itself is an abstract class, but will create an appropriate subclass if a compatible source is found for the given input_url.

>>> EventSource(input_url="dataset://gamma_test_large.simtel.gz")
<ctapipe.io.simteleventsource.SimTelEventSource ...>

An EventSource can also be created through the configuration system, by passing config or parent as appropriate. E.g. if using EventSource inside of a Tool, you would do: >>> self.source = EventSource(parent=self) # doctest: +SKIP

To loop through the events in a file: >>> source = EventSource(input_url=”dataset://gamma_test_large.simtel.gz”, max_events=2) >>> for event in source: … print(event.count) 0 1

NOTE: Every time a new loop is started through the source, it tries to restart from the first event, which might not be supported by the event source.

It is encouraged to use EventSource in a context manager to ensure the correct cleanups are performed when you are finished with the source:

>>> with EventSource(input_url="dataset://gamma_test_large.simtel.gz", max_events=2) as source:
...    for event in source:
...        print(event.count)
0
1

NOTE: For effiency reasons, most sources only use a single ArrayEvent instance and update it with new data on iteration, which might lead to surprising behaviour if you want to access multiple events at the same time. To keep an event and prevent its data from being overwritten with the next event’s data, perform a deepcopy: some_special_event = copy.deepcopy(event).

Attributes

input_urlstr: Path to the input event file.
max_eventsint: Maximum number of events to loop through in generator
allowed_tels: Set or None: Ids of the telescopes to be included in the data. If given, only this subset of telescopes will be present in the generated events. If None, all available telescopes are used.

Attributes Summary

`allowed_tels`	An instance of a Python set.
`datalevels`	The datalevels provided by this event source
`input_url`	A path Trait for input/output files.
`is_simulation`	Weither the currently opened file is simulated
`is_stream`	Bool indicating if input is a stream.
`max_events`	An int trait.
`obs_ids`	The observation ids of the runs located in the file Unmerged files should only contain a single obs id.
`subarray`	Obtain the subarray from the EventSource

Methods Summary

`from_config`([config, parent])	Find compatible EventSource for the EventSource.input_url traitlet specified via the config.
`from_url`(input_url, **kwargs)	Find compatible EventSource for input_url via the `is_compatible` method of the EventSource
`has_any_datalevel`(datalevels)	Check if any of `datalevels` is in self.datalevels
`is_compatible`(file_path)	Abstract method to be defined in child class.

Attributes Documentation

allowed_tels¶: An instance of a Python set.

datalevels¶

The datalevels provided by this event source

Returns

tuple[ctapipe.io.DataLevel]

input_url¶

A path Trait for input/output files.

Attributes

exists: boolean or None: If True, path must exist, if False path must not exist
directory_ok: boolean: If False, path must not be a directory
file_ok: boolean: If False, path must not be a file

is_simulation¶

Weither the currently opened file is simulated

Returns

bool

is_stream¶

Bool indicating if input is a stream. If it is then it is incompatible with ctapipe.io.eventseeker.EventSeeker.

TODO: Define a method to detect if it is a stream

Returns

bool: If True, then input is a stream.

max_events¶: An int trait.

obs_ids¶

The observation ids of the runs located in the file Unmerged files should only contain a single obs id.

Returns

list[int]

subarray¶

Obtain the subarray from the EventSource

Returns

ctapipe.instrument.SubarrayDecription

Methods Documentation

classmethod from_config(config=None, parent=None, **kwargs)[source]¶

Find compatible EventSource for the EventSource.input_url traitlet specified via the config.

This method is typically used in Tools, where the input_url is chosen via the command line using the traitlet configuration system.

Parameters

configtraitlets.config.loader.Config: Configuration created in the Tool
kwargs: Named arguments for the EventSource

Returns

instance: Instance of a compatible EventSource subclass

classmethod from_url(input_url, **kwargs)[source]¶

Find compatible EventSource for input_url via the is_compatible method of the EventSource

Parameters

input_urlstr: Filename or URL pointing to an event file
kwargs: Named arguments for the EventSource

Returns

instance: Instance of a compatible EventSource subclass

has_any_datalevel(datalevels) → bool [source]¶

Check if any of datalevels is in self.datalevels

Parameters

datalevels: Iterable: Iterable of datalevels

abstract static is_compatible(file_path)[source]¶

Abstract method to be defined in child class.

Perform a set of checks to see if the input file is compatible with this file event_source.

Parameters

file_pathstr: File path to the event file.

Returns

compatiblebool: True if file is compatible, False if it is incompatible