class ConstantValue(object):
    # 1. Option Type
    AMERICAN = 'American'
    EUROPEAN = 'European'
    
    # 2. CallOrPutOrStock Type
    CALL = 'call'
    PUT = 'put'
    STOCK = 'stock'
        
    # 3. Trade Type
    BUY = 'buy'
    SELL = 'sell'
    
    LONG = 'buy'
    SHORT = 'sell'
    
    BLACK_SHOLES = 'BlackSholes'
    BINOMIAL_TREE = 'BinomialTree'
    MONTE_CARLO = 'MonteCarlo'
    
    QUERY_PAGE_SIZE = 10