Someone

def whereis(s1,s2):    '''whereis(str, str)-> int/boolean        Returns the index number of the first occurence of the single letter     string s2 in the string s1. Returns False if the parameters given are not     strings and if s2 is not a single letter in length.'''    if ( type(s1) != str ) or ( type(s2) != str ):        return False        if len(s2) != 1:        return False        return s1.find(s2)