@originate ( output, [extras,...] )¶

Purpose:

Creates (originates) a set of starting file without dependencies from scratch (ex nihilo!)

Only called to create files which do not exist.

Invoked onces (a job created) per item in the output list.

Note

The first argument for the task function is the output. There is by definition no input for @originate

Example:
from ruffus import *
@originate(["a", "b", "c", "d"], "extra")
def test(output_file, extra):
    open(output_file, "w")

pipeline_run()
>>> pipeline_run()
    Job  = [None -> a, extra] completed
    Job  = [None -> b, extra] completed
    Job  = [None -> c, extra] completed
    Job  = [None -> d, extra] completed
Completed Task = test

>>> # all files exist: nothing to do
>>> pipeline_run()

>>> # delete 'a' so that it is missing
>>> import os
>>> os.unlink("a")

>>> pipeline_run()
    Job  = [None -> a, extra] completed
Completed Task = test
Parameters:

output = output

Can be a single file name or a list of files

Each item in the list is treated as the output of a separate job

extras = extras

Any extra parameters are passed verbatim to the task function

If you are using named parameters, these can be passed as a list, i.e. extras= [...]

Any extra parameters are consumed by the task function and not forwarded further down the pipeline.