Source code for b2luigi.core.parameter
import hashlib
import luigi
from luigi.parameter import _no_value
from inspect import signature
[docs]
def wrap_parameter():
"""
Monkey patch the parameter base class (and with it all other parameters(
of luigi to include three additional parameters in its constructor:
``hashed``, ``hash_function`` and ``hidden``.
Enabling the ``hashed`` parameter will use a hashed version of the
parameter value when creating file paths our of the parameters of a task
instead of the value itself. By default an md5 hash is used. A custom
hash function can be provided via the ``hash_function`` parameter. This
function should take one input, the value of the parameter. It is up
to the user to ensure a unique string is created from the input.
This is especially useful when you have list, string or dict parameters,
where the resulting file path may include "/" or "{}".
With the ``hidden`` parameter, you can control whether the parameter
should be hiddened in the task's output directory structure when using
:meth:`add_to_output <b2luigi.Task.add_to_output>`.
.. caution::
This will remove the parameter from the unique output of the task,
so be sure to add it back, e.g. into the output file name:
.. code-block:: python
class MyTask(b2luigi.Task):
iddened_parameter = b2luigi.Parameter(hidden=True)
def output(self):
yield self.add_to_output(f"test_{self.hiddened_parameter}.txt")
"""
import b2luigi
parameter_class = b2luigi.Parameter
def serialize_hashed(self, x):
if self.hash_function is None:
return "hashed_" + hashlib.md5(str(x).encode()).hexdigest()
else:
return self.hash_function(x)
old_init = parameter_class.__init__
def __init__(self, hashed=False, hash_function=None, hidden=None, *args, **kwargs):
old_init(self, *args, **kwargs)
if hash_function is not None:
n_params = len(signature(hash_function).parameters)
assert n_params == 1, "Custom hash function can have only" f" 1 argument, found {n_params}"
self.hash_function = hash_function
if hashed:
self.serialize_hashed = lambda x: serialize_hashed(self, x)
self.hidden = hidden if hidden is not None else not self.significant
if not self.significant and not self.hidden:
raise ValueError("Parameter cannot be both hidden=False and significant=False.")
parameter_class.__init__ = __init__
class BoolParameter(luigi.BoolParameter):
"""Copied BoolParameter without default value"""
def __init__(self, **kwargs):
kwargs.setdefault("default", _no_value)
luigi.Parameter.__init__(self, **kwargs)