CSCI/CMPE 4341 Topic: CSCI/CMPE 4341 Topic: Programming in PythonProgramming in Python

Chapter 1: Introduction to PythonChapter 1: Introduction to Python

Xiang Lian

The University of Texas – Pan American

Edinburg, TX 78539

lianx@utpa.edu

1

Objectives

• In this chapter, you will– Know requirements of this course

– Recall basic components in a computer system

– Learn the evolution of programming language

– Refresh your memory about the structured programming vs. object-oriented programming

– History of Python

2

Background Required

• C++ Programming– If you made an A in 1370/1170 you will do fine

with some effort

– If you have already taken 2380, you will find this course not very difficult

• You need to be able to look up how to get things done (for example, look up syntax)

3

Programming, Programming, Programming

• This class is unlike other courses in that you will spend a lot of time doing actual programming

• You should never copy a program from someone else• Even if your program does not perform as good as

someone else’s, you should submit what you have

• You should not hesitate to ask questions in class

4

Assignments

• Unless I announce it, programs are due in one week after assignment is given in class, or posted • Occasionally, I will give two weeks for difficult

programs

• You should work on a program the same day it is assigned• That way you can ask questions during the

following class period

5

Use of the Textbook

• I will not be covering chapter by chapter

• I will cover important points needed to complete the assignments

• You need to search the index in the back to find the topic needed for each assignment

• You can also obtain help from websites of online resources

6

Versions of Python• Python IDE software:– https://www.python.org/downloads/ – Python 2.2.X– Python 3.4.X

• You will find differences for different versions Python– Thus, in your assignments, you need to specify which

version (3.4.2 recommended) you are using

7

The Time for Class

• I expect to hold the class for little over an hour each time, with a 10-minute break

• For assignments, please do not exchange programs with each other, just ideas

• For projects, you can discuss the project with your study group members

8

Study Group

• Please form a team with 3-4 team members

• Each team needs to finish one programming project, including:– A project report (e.g., problem description, background,

solution, implementation, experimental settings, empirical evaluation, and screen captures of graphical interface);

– A statement of tasks for each team member;

– Source code;

– Demonstration (5 minutes); and

– Presentation (10-15 minutes).

9

Python 3.4 GUI

Python 3.4 Command Line

10

CSCI 1380: Elements of a Computer System

• Hardware– CPU

–Main memory

– Secondary storage

– Input / Output devices

• Software– System programs

– Application programs (e.g. Python IDE)

11

Programming Languages

• Machine language

• Assembly language

• High-level language– E.g., Visual Basic, C, C++, Visual C#, Java,

Python

12

Structured (Procedural) Programming Technology

• Early Software Development– Complex and costly for businesses (1960s)• Costs exceeded budgets

• Final products unreliable

– Research led to structured programming• Disciplined approach to programming

– Programs clear and easy to modify

• Several languages resulted from research– C, Pascal, Ada

13

Object-Oriented Programming Technology

• We humans are very good in recognizing and working with objects, such as a pen, a dog, or a human being

• We learned to categorize them in such a way that make sense to us. –We may categorize them as animate object,

inanimate objects, pets, friends, etc.

14

Object-Oriented Programming Technology(cont'd)

• We some times classify objects based on their attributes, for example, green apples or red apples, fat or slim people, etc.

• If you think about it each object has many attributes. – If I ask you list the attributes of an orange, you

probably could list many things such as color, shape, weight, smell, etc.

15

Object-Oriented Programming Technology (cont'd)

• In addition to attributes, all objects exhibit behaviors.

• A dog eats, barks, wags its tail, plays, and begs. – A dog exhibits many more other behaviors than

this short list.

• Another thing we need to remember about objects is that objects interact between each other

16

History of Python

• Created in 1989 by Guido van Rossum– Created as a scripting language for administrative

tasks

– Based on All Basic Code (ABC) and Modula-3• Added extensibility

– Named after comic troupe Monty Python

• Released publicly in 1991– Growing community of Python developers

– Evolved into well-supported programming language

17

Python

• Python is a scripting language– It is not compiled as an executable file

• Python– Structured programming• Like C

– Object-oriented programming• Like C++

• Class and object

18

To Get Python Tutorial/Documentation

• Visit:– Python How to Program, Deitel et al.

– Learning to Program Using Python, Cody Jackson

– Python Documentation

19

Hello Program# Fig. 2.1: fig02_01.py# Printing a line of text in Python.

print ("Welcome to Python Programming Class!")

# Results:# Welcome to Python Programming Class!

Note: parentheses are needed for Python 3.4.X, but

not necessary for Python 2.2.X (used in Textbook)

20

Hello Program (cont'd)

• print ("Welcome to Python Programming Class!")

• print ("-- Xiang!")

-----------------------------------------------------------

• print ("Welcome to Python Programming Class! \n-- Xiang!")

21

Your First Assignment

• Assignment #1

• The purpose of this assignment is to practice writing to shell and command-line window using Python 3.4. It is a simple assignment.– Please submit Program listing and a screen capture

of the program run.

– Follow the textbook examples to add comments as documentation.

22

Assignment Submission

• Make sure to include your name, assignment number, date due and date completed on each assignment you submit

• Assignment should be submitted in a zip folder with your name and assignment number appearing on the tab

• Submit your assignments to the Blackboard

23

Exercises

• Install Python 3.4 on your machine

• Find a good Python IDE (other than that on www.python.org) for programming graphical user interface (GUI)

• How do you output the string “Total Square Feet: 1238” to the shell/command-line window. – Assume that 1238 in an integer stored in a variable

called sqFt.

• Describe 3 differences of Python from C++

24

25