helper function for overly long dataset names (overcoming a monogdb limitation)

omx_dslongname.py

def put_longname(store, obj, name, **kwargs):
    """ helper function to overcome mongodb limitation on namespace length
    
    Only use to store Pandas dataframes and series
    
    Usage:
        Copy/paste this function into your code base
       
        # instead of
        meta = om.datasets.put(obj, name)
        
        # use 
        meta = put_longname(om.datasets, obj, name)
        
    How it works:
        1. Generates a hashed name which is safe to
           use within the mongodb namespace length limits
        2. stores the object
        3. sets the metadata name to the given name, 
           which can be arbitrary length (within mongodb 
           key lenght limits)
        
    See also:
        https://github.com/omegaml/omegaml/issues/153
    """ 
    from hashlib import md5
    if not kwargs.get('append') or kwargs.get('replace'):
        kwargs.pop('append', False)
        kwargs.pop('replace', False)
        store.drop(name, force=True)
    if store.metadata(name) is None:
       safe_name = md5(name.encode('utf8')).hexdigest()
       meta = store.put(obj, safe_name, **kwargs)
       meta.name = name
       meta.save()
    else:
       meta = store.put(obj, name, **kwargs)
    return meta