libera_utils.spice_utils.ensure_spice

libera_utils.spice_utils.ensure_spice(f_py: Callable = None, time_kernels_only: bool = False)

Before trying to understand this piece of code, read this: https://stackoverflow.com/questions/5929107/decorators-with-parameters/60832711#60832711

Decorator/wrapper that tries to ensure that a metakernel is furnished in as complete a way as possible.

Control flow overview:

1. Try simply calling the wrapped function naively.

   • SUCCESS? Great! We’re done.

   • SpiceyError? Go to step 2.

2. Furnish metakernel at SPICE_METAKERNEL

   • SUCCESS? Great, return the original function again (so it can be re-run).

   • KeyError? Seems like SPICE_METAKERNEL isn’t set, no problem. Go to step 3.

Usage:

Three ways to use this object

1. A decorator with no arguments

@ensure_spice
def my_spicey_func(a, b):
    pass

2. A decorator with parameters. This is useful if we only need the latest SCLK and LSK kernels for the function involved.

@ensure_spice(time_kernels_only=True)
def my_spicey_time_func(a, b):
    pass

3. An explicit wrapper function, providing a dynamically set value for parameters, e.g. time_kernels_only

wrapped = ensure_spice(spicey_func, time_kernels_only=True)
result = wrapped(*args, **kwargs)

Parameters:

• f_py (Callable) – The function requiring SPICE that we are going to wrap if being used explicitly, Otherwise None, in which case ensure_spice is being used, not as a function wrapper (see l2a_processing.py) but as a true decorator without an explicit function argument.

• time_kernels_only (bool, Optional) – Specify that we only need to furnish time kernels (if SPICE_METAKERNEL is set, we still just furnish that metakernel and assume the time kernels are included.

Returns:

Decorated function, with spice error handling

Return type:

Callable