Indentation is critical in Python

Indentation plays a vital role in Python. Let's look at an R program. Anything between a pair of curly braces belongs to the same logic block. If we have multiple lines, the indentation is not important for R programs, as shown in the following code:

pv_f<-function(fv,r,n) {   # this is an R program
    pv<-fv*(1+r)^(-n)
pv
}

To achieve the same result in Python, we use indentations instead. This means that all the lines with the same indentation belong to the same scope, as shown in the following code:

def pv_f(fv,r,n):
    pv=fv/(1+r)**n
    return pv

The following are the ways to input values:

• In the preceding example, pv_f(100,0.1,1), we input three values, 100, 0.1, and 1. There is no ambiguity that 100 is the future value, 0.1 is the discount rate, and 1 is the number of periods since the input variables are arranged this way. This is the first way to input values into a function.

• The second way to input values is based on key words. The advantage...