def isChildUri(parentUri, childUri):
    """Return True, if childUri is a child of parentUri.
    
    This function accounts for the fact that '/a/b/c' and 'a/b/c/' are
    children of '/a/b' (and also of '/a/b/').
    Note that '/a/b/cd' is NOT a child of 'a/b/c'. 
    """
    return parentUri and childUri and childUri.rstrip("/").startswith(parentUri.rstrip("/")+"/")