def find(seq, predicate):
    """Find index in seq for which predicate is True.

    Searches the sequence and returns the index of the element for
    which the predicate evaluates to True.  Returns -1 if the
    predicate does not evaluate to True for any element in seq.

    """
    for i, elt in enumerate(seq):
        if predicate(elt):
            return i
    return -1