ERROR:root:Exception in dhanhq>>place_order: 'NoneType' object has no attribute 'upper'

def place_order(dhan, symbol, exchange, side, quantity, order_type, price):
exchange_segment = get_exchange(dhan, exchange)
side = get_side(dhan, side)
order_type = get_order_type(dhan, order_type)
order_id = dhan.place_order(security_id=symbol,
exchange_segment=exchange_segment,
transaction_type=side, quantity=quantity,
order_type=order_type,
product_type=dhan.INTRA,
price=price)