def mask_zero(data, tech, var='r', locations=None):
    df = data[var][tech]
    if locations:
        df = df.loc[:, locations]
    # Retain original resolution everywhere by default (0)
    mask = pd.Series(0, index=list(range(len(df))))
    # Sum over all locations to find those times where the data==0 everywhere
    mask[df.sum(1) <= 0] = 1
    mask.name = 'mask'
    return mask
Returns an iterator of docnums matching this query.
dataset/ETHPy150Open calliope-project/calliope/calliope/time_masks.py/mask_zero--crossover with--dataset/ETHPy150Open dokipen/whoosh/src/whoosh/query.py/Query.docs