Refactor Python position Example

[ax3l]

Second change for the example how to combine position and positionOffset to make it more general.

The functions provided now are corrected in namings and usable for general record components even outside of the particle scope (e.g., one can use them to read scalar and vector mesh components).

I still did not add doc strings since I try not to blow up the inline example since it is already pretty large.

outdated: The allocate option is quite of a fancy thing in case one wants to transparently allocate an ndarray to access it via [] later on but could be removed.

Otherwise I can also keep it like this:

def get_component(group, component_name):
    record_component = group[component_name]
    unitSI = record_component.attrs["unitSI"]

    if is_const_record_component(record_component):
        return record_component.attrs["value"], unitSI
    else:
        return record_component.value, unitSI

instead of

def get_component(group, component_name, allocate=False):
    record_component = group[component_name]
    unitSI = record_component.attrs["unitSI"]

    if is_const_component(record_component):
        cvalue = record_component.attrs["value"]
        if allocate:
            return cvalue * \
                numpy.ones(shape=record_component.attrs["shape"],
                           dtype=record_component.attrs["value"].dtype),
                unitSI
        else:
            return cvalue, unitSI
    else:
        return record_component.value, unitSI

update: yes, that is probably better... too fancy and not necessary to know for most people I guess...

[RemiLehe]

Great. Thanks for the update.
I also prefer it without the allocate option.