Chapter 3. Using Python as a Financial Calculator

In this chapter, we will learn how to write simple functions such as estimation of the present value for a given future value, the present value of an annuity, and the monthly payment of our mortgage. In addition, we will show how to combine two dozens of small functions as a big Python program and use it for financial estimation. In other words, we plan to create a financial calculator using Python.

In particular, we will cover the following topics:

• Writing a Python function without saving it

• Why indentation is critical in Python

• Three ways to input values and a default value for an input variable

• Using dir() to check the existence of our newly generated function

• Saving our pv_f() function

• Activating our function from our Python editor using import()

• While debugging a program, activate your program from a Python editor

• import test01 versus from test01 import *

• Removing a function using the del() method

• Generating our own module

• Two types of comments...