Mastering pandas for Finance

Modeling a portfolio with pandas

A basic portfolio model consists of a specification of one or more investments and their quantities. A portfolio can be modeled in pandas using a DataFrame with one column representing the particular instrument (such as a stock symbol) and the other representing the quantity of the item held.

The following command will create a DataFrame representing a portfolio:

In [2]:
   def create_portfolio(tickers, weights=None):
       if (weights is None): 
           shares = np.ones(len(tickers))/len(tickers)
       portfolio = pd.DataFrame({'Tickers': tickers, 
                                 'Weights': weights}, 
                                index=tickers)
       return portfolio

Using this, we can create a portfolio of two instruments, Stock A and Stock B. The amount of shares for each is initialized to ...