How to structure python programs - Program Narrative

 Imagine the following high-level logical flow for a simple report generator program:

Read input data

Perform calculations

Write report

Notice how each stage (after the first one) depends on some byproduct or output of its predecessor:

Read input data

Perform calculations (based on input data)

Write report (based on calculated report data)

This is just about structuring the code in such a way that methods come like this below 

def read_input_file(filename):

    pass

def generate_report(data):

    pass

def write_report(report):

    pass

data = read_input_file('data.csv')

report = generate_report(data)

write_report(report)

References:

https://dbader.org/blog/how-to-structure-python-programs