pandas.Index.fillna — pandas 0.18.1 documentation (original) (raw)
value : scalar
Scalar value to use to fill holes (e.g. 0). This value cannot be a list-likes.
downcast : dict, default is None
a dict of item->dtype of what to downcast if possible, or the string ‘infer’ which will try to downcast to an appropriate equal type (e.g. float64 to int64 if possible)