This PR adds workflow parameters, a way to parametrize workflows in a way that makes the branch lookup dynamic, based on values in the branch map.
From the README:
Example code:
import law
import luigi
class MyWorkflow(law.LocalWorkflow):
option_a = law.WorkflowParameter()
option_b = law.WorkflowParameter(cls=luigi.IntParameter)
@classmethod
def create_branch_map(cls, params):
return {
0: {"option_a": "foo", "option_b": 123},
1: {"option_a": "bar", "option_b": 456},
2: {"option_a": "foo", "option_b": 456},
# ... you could add more branches here
}
def run(self):
# this run method is only called by *branches*, i.e.,
# - self.branch will be 0, 1 or 2, and
# - self.branch_data will refer to the corresponding dictionary in the branch map
pass # ... implementation
option_a and option_b are law.WorkflowParameters that can optionally define a cls (or inst) of a other parameter object that is used for parameter parsing and serialization (as always).
create_branch_map becomes a @classmethod and receives all task parameters in a dictionary params.
This is necessary since the automatic lookup of branches based on the values of workflow parameters, internally, must happen before the task is actually instantiated.
As a result, parameters can be defined verbosely on the command line, translate to branch values, and configure which branches are run by the workflow:
--option-a foo --option-b 123 → finds branch=0 (but for this, you probably wouldn't need a workflow in the first place)
--option-a foo → finds branches=[0, 2] and runs them as a workflow
--option-b 456 → finds branches=[1, 2] and runs them as a workflow
--option-b 123 → finds branches=[0] and runs it in a workflow; in particular, this is not a branch as --option-a is not specified, meaning we're "not interested in any particular value of option_a, just run all that are found".
This PR adds workflow parameters, a way to parametrize workflows in a way that makes the branch lookup dynamic, based on values in the branch map.
From the README:
Example code:
option_aandoption_barelaw.WorkflowParameters that can optionally define acls(orinst) of a other parameter object that is used for parameter parsing and serialization (as always).create_branch_mapbecomes a@classmethodand receives all task parameters in a dictionary params. This is necessary since the automatic lookup of branches based on the values of workflow parameters, internally, must happen before the task is actually instantiated.As a result, parameters can be defined verbosely on the command line, translate to branch values, and configure which branches are run by the workflow:
--option-a foo --option-b 123→ findsbranch=0(but for this, you probably wouldn't need a workflow in the first place)--option-a foo→ findsbranches=[0, 2]and runs them as a workflow--option-b 456→ findsbranches=[1, 2]and runs them as a workflow--option-b 123→ findsbranches=[0]and runs it in a workflow; in particular, this is not a branch as--option-ais not specified, meaning we're "not interested in any particular value of option_a, just run all that are found".Closes #131, #137.