remap_fields.py

import jmespath


def remap_fields(fieldmap, data, loader=None, *, jmes=True, **defaults):
    '''Map data.

    >>> remap_fields({'price': 'productPrice'}, {'productPrice': 5.00})
    {'price': 5.00}

    >>> remap_fields({'price': ['producPrice', 'finalPrice']}, {'finalPrice': 5.00})
    {'price': 5.00}

    WARNING: JMESPath does not differentiate between absent and null fields.
    This function will regard null fields as absent when using JMESPath.
    '''
    out = {}
    for ours, theirs in fieldmap.items():
        if not isinstance(theirs, (list, tuple)):
            theirs = [theirs]

        for their in theirs:
            if jmes:
                val = jmespath.search(their, data)
                if val is not None:
                    break
            elif their in data:
                val = data[their]
                break
        else:
            val = defaults.get(ours)
        out[ours] = val
        if loader:
            loader.add_value(ours, val)
    return out