giving.utils

giving.utils.keyword_decorator(deco)

Wrap a decorator to optionally takes keyword arguments.

giving.utils.lax_function(fn)

Add a **kwargs argument to fn if it does not have one.

fn is not modified. If it has a varkw argument, fn is returned directly, otherwise a new function is made that takes varkw and does nothing with them (it just drops them)

Example

@lax_function
def f(x):
    return x * x

f(x=4, y=123, z="blah")  # works, returns 16. y and z are ignored.
giving.utils.reducer(func=None, default_seed=NotSet, postprocess=NotSet)

Create a reduction operator.

Note

If func is not given, this returns a decorator.

  • If func is a function, it should have the signature func(accum, x) where accum is the last result and x is the new data.

  • If func is a class, it should have the following methods:

    • reduce(accum, x), used when scan is boolean (scan=False or scan=True)

    • roll(accum, x, drop, last_size, current_size) (see giving.operators.roll()), used when scan is an integer (scan=n). It should implement an optimized way to reduce over the last n elements of a sequence. Note that last_size and current_size cannot exceed n.

    • Any arguments to __init__ will be passed over when the operator is called.

Example:

@reducer
def sum(last, new):
    return last + new

@reducer
class sum:
    def reduce(self, last, new):
        return last + new

    def roll(self, last, new, drop, last_size, current_size):
        result = last + new
        if last_size == current_size:
            result -= drop
        return result
Parameters

  • func – A function or class that defines the reduction.

  • default_seed – The default seed to start the reduction.

  • postprocess – A postprocessing step to apply to the result of the operator.

Returns

A reduction operator that takes a scan argument to perform a scan or roll operation instead of reduce.

giving.utils.reduced_traceback(skip=['giving.*', 'rx.*'], depth=2)

Create a traceback from the current frame, minus skipped modules.

Parameters

  • skip – List of modules to skip.

  • depth – Depth at which to start.