def has_common_column(a, b):
    """
    Returns:
        True if A & B have at least one common column
    """
    columns_a = [(c.name, c.data_type) for c in a.columns.columns]
    columns_b = [(c.name, c.data_type) for c in b.columns.columns]
    if list(set(columns_a) & set(columns_b)):
        return True
    return False