# merge¶

## @merge ( input, output, [extras,...] )¶

Purpose:

Merges multiple input into a single output.

Only out of date tasks (comparing input and output files) will be run

Example:

@merge(previous_task, 'all.summary')
def summarize(infiles, summary_file):
pass


Parameters:

can be a:

File names are taken from the output of the specified task(s)

2. (Nested) list of file name strings.
File names containing *[]? will be expanded as a glob.

E.g.:"a.*" => "a.1", "a.2"

• output = output

Specifies the resulting output file name(s).

• 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.

See here for more advanced uses of merging.