Lecture Notes on 23 Aug 2023

* Overview of Python

* Write the Hello World program

def main():
  print ("Hello World!")
main()

* Characterset: ASCII and Unicode

* Variables: 
    - must start with a letter or underscore
    - can be followed by n number of letters, digits, and underscores
    - cannot be a reserved word

* Types - strongly typed or weakly typed

* Statement and expressions

* Assignment statement

* Operators
  - Arithmetic: + - * / // % **
  - Comparison: < <= > >= == !=
  - Boolean: not, and, or
  - Bitwise: ~, &, |, ^
  - Shift: <<, >>

* Conditionals: if-else, if-elif-else

* Loops: while, for

* Lists: 1D, 2D, nD

* Tuples, Sets, Dictionaries

* Input / Output

* Functions
  - built-in
  - math, random, sys
  - user defined

* Class

* Principles of Objected-Oriented Programming
  - Abstraction
  - Encapsulation
    - Information Hiding
  - Inheritance
  - Polymorphism

* Characteristics of Good Software Design
  - Correctness
  - Efficiency:  time, space
  - Maintainability: modular and well documented
  - Aesthetics: elegance in the algorithm and coding
  - Usability: how easy is it for the user to understand and use the code
  - Scalability: how easy is it to increase the scope of the program

* Solution of Digit Swap on Kattis

#! /usr/bin/python3

# file: digitswap.py

# date: 23 Aug 2023

import sys

def main():
  line = sys.stdin.readline ()
  line = line.strip()

  n = int(line)
  m = (n % 10) * 10 + (n // 10)

  print (m)

if __name__ == "__main__":
  main()