将类函数除以数字时，“无法调用浮点对象”

Question

I have a class Portfolio with a method portfolio_risk(self, year) .If I try and divide it by a number I get the error

Float object is not callable

From my understanding the error is arising due to the parenthesis from the portfolio_risk method but I need to call the method to do the calculation. Is there a different way I could write this code to avoid the error?

if Portfolio.portfolio_risk(1)/5 < 7:
    print('meets criteria')

EDIT: I have added some more information below:

My class is as follows:

class Portfolio(import_data):

    def __init__(self, number_yrs):

        self.debt = [0 for i in range(number_yrs)]

        # the import_csv function just pulls a data table from excel and creates a list
        # the list is 2D and creates a property called self.sub_portfolio in this class
        # all the values imported from the csv file are of type float 
        self.import_csv('sub_portfolio') 
        self.debt[0] = self.debt_portfolio

    def portfolio_risk(self, year):

        # this sums up the risk column of a portfolio to give total risk for a year

        self.portfolio_risk = sum(a[0] for a in self.debt[year])
        return(self.portfolio_risk)

If I create an instance of this class:

new_portfolio = Portfolio(5)

My Portfolio class is contained in a file portfolio_class.py and the following line works correctly within this file when I test it:

print(new_portfolio.portfolio_risk(0))

In another file, analysis.py, I have the following code:

 nyears = 10
 real_portfolio = Portfolio(nyears)
 for i in range(nyears):

    if i > 0:

        # first use last prior year portfolio
        the_debt_portfolio.debt[i] = the_debt_portfolio.debt[i-1]


    if real_portfolio.portfolio_risk(i)/ 5 < 7:

        print('this is within the risk band')

I now seem to be getting the error:

  line 29, in portfolio_risk
  self.portfolio_risk = sum(a[0] for a in self.portfolio_risk[year])
  TypeError: 'int' object is not iterable

And not the Float object is not callable error

Answer 1

There are a couple of problems with your code:

1. If should be if (lowercase i );
2. You need an instance of Portfolio in order to be able to call the (non-static) method.

That said, it's not entirely clear how you'd get that exact exception. One possibility is that somewhere you rebind portfolio_risk to a float . Even then, the capitalized If would produce a syntax error.

I think the best way forward is for you to fix the two problems mentioned above and, if that doesn't help, post more code.

Answer 2

If the method is defined like this

class Portfolio(object):
    def portfolio_risk(self, year):
        return 1

then you must have an instance of Portfolio :

p = Portfolio()
if p.portfolio_risk(1) / 5 < 7:
    # do something

Answer 3

Try something like this:

portfolio = Portfolio() # you may need to pass some parameters

if portfolio.portfolio_risk(1) / 5 < 7:
    print('meets criteria')

Of course, if portfolio_risk is a field and not a method you'll still get that error.