optional function arguments

[random guy]

I have an interesting issue with having an optional argument to a function that is an property of a class:

I want to do the following

def addStockToMarket(self, stockTicker, startDate=self.tradingDay):

where tradingDay is a property of the class that is set when the class object is constructed. the issue is that it doesnt like that i am doing that because i guess it doesnt know what "self" is at that point in the function definition since it is getting self passed into it.

is there any way around this issue other than making seperate functions for each set of arguments?

[saeras]

You could set startDate=None or something and then make an if check. example:

def addStockToMarket(self, stockTicker, startDate=None):
    if startDate == None:
        startDate = self.tradingDay

I don't know if doing this is generally accepted though.

[manux]

I don't know if doing this is generally accepted though.

In fact, that's the generally recommended method, and you can add more conditions there to verify the validity of the argument.

def addStockToMarket(self, stockTicker, startDate=None):
    if startDate == None or not isValidDate(startDate):
        startDate = self.tradingDay

Since "None" probably wont be a valid date, you can just write:

if not isValidDate(startDate):
    startDate = self.tradingDay