human
What is a the Python code you requested given the following:
Complete the below
@directive(('dependencies', 'dependency_types'))
def depends_on(spec, when=None, type=None):

    ''''Creates a dict of deps with specs defining when they apply.
    This directive is to be used inside a Package definition to declare
    that the package requires other packages to be built first.
    @see The section "Dependency specs" in the Spack Packaging Guide.'
    '''
assistant
#Here is the Python code you requested.
    def _execute(pkg):
        _depends_on(pkg, spec, when=when, type=type)
    return _execute