# Context

This module implements the Prefect context that is available when tasks run.

Tasks can import prefect.context and access attributes that will be overwritten when the task is run.

Example:

import prefect.context

with prefect.context(a=1, b=2):
    print(prefect.context.a) # 1

print(prefect.context.a) # undefined

Prefect provides various key / value pairs in context that are always available during task runs:

Variable	Description
`date`	an actual datetime object representing the current time
`today`	the current date formatted as `YYYY-MM-DD`
`today_nodash`	the current date formatted as `YYYYMMDD`
`yesterday`	yesterday's date formatted as `YYYY-MM-DD`
`yesterday_nodash`	yesterday's date formatted as `YYYYMMDD`
`tomorrow`	tomorrow's date formatted as `YYYY-MM-DD`
`tomorrow_nodash`	tomorrow's date formatted as `YYYYMMDD`
`logger`	the logger for the current task
`config`	the complete Prefect configuration object that is being used during this run
`flow_name`	the name of the current flow
`scheduled_start_time`	a datetime object representing the scheduled start time for the flow run; falls back to `now` for unscheduled runs
`parameters`	a dictionary of parameter values for the current flow run
`map_index`	the map index of the current task (if mapped, otherwise `None`)
`task_name`	the name of the current task
`task_full_name`	the name of the current task, including map index
`task_slug`	the slug of the current task
`task_tags`	the tags on the current task
`task_run_count`	the run count of the task run - typically only interesting for retrying tasks
`task_loop_count`	if the Task utilizes looping, the loop count of the task run
`task_loop_result`	if the Task is looping, the current loop result

In addition, Prefect Cloud supplies some additional context variables:

Variable	Description
`flow_id`	the id of the current flow
`flow_run_id`	the id of the current flow run
`flow_run_version`	the state version of the current flow run
`flow_run_name`	the name of the current flow run
`task_id`	the id of the current task
`task_run_id`	the id of the current task run
`task_run_version`	the state version of the current task run
`resume`	boolean showing if the current task run was manually restarted

Users can also provide values to context at runtime. For more information, see the Context concept doc.

class

prefect.utilities.context.Context

(*args, **kwargs)[source]

A thread safe context store for Prefect data.

The Context is a DotDict subclass, and can be instantiated the same way.

Args:

*args (Any): arguments to provide to the DotDict constructor (e.g., an initial dictionary)
**kwargs (Any): any key / value pairs to initialize this context with

This documentation was auto-generated from commit n/a
on July 1, 2021 at 18:35 UTC