CSC1024 Programming Principles: Week 02

• CSC1024 is Programming Principles, Week 02
• The subject leader is Dr Danish Mahmood Khan, a Senior Lecturer at the Academic Staff Office (UW 3-2); his email is [email protected]

Assessment Dates / Marks Allocation

• Quiz 1 accounts for 25% of the grade and covers weeks 01-02
• Quiz 1 will occur during the lecture in Week 3, on the 26th of Feb 2025, and will consist of MCQs
• Quiz 2 accounts for 25% of the grade and covers weeks 03-06
• Quiz 2 will occur during the lecture in Week 6, on the 20th or 21st of March 2025, and consists of MCQs.
• The Final Project accounts for 50% of the grade and will be released in Week 4
• The Final Project's online submission is due March 23rd, 2025
• The demonstration and presentation of the Final Project will occur during the Lab session in Week 7; contact the Lab Instructor for more details

Course Requirements

• Students must pass both the coursework and final project components to pass the course
• The passing grade is 40/100

Course Content

• Week 1 covers the introduction to CSC1024, problem-solving, programming style, and getting started with Python
• Week 2 covers expressions and variable assignments, inputs/outputs/variables, data types and operations, and error handling/debugging; practical assignments 01 and 02 are related to this week's content
• Week 3 includes decision-making, flowcharts, Python interpreter and text files. Test 01 is on Feb 26th, 2025. There are no physical classes on the 27th and 28th. Practical assignments 03 and 04 are related to week 3's content.
• Week 4 covers iterations (For Loop), nested loops and import library; Practical assignments 05 and project assignments are related to this week's content.
• Week 5 includes Data Structures and Iterations (While Loop); Practical assignments 06 and 07 are related to week 5's content.
• Week 6 covers Functions; Test 02 is on March 20th for Group 1 and March 21st, 2025 for Group 2; Practical assignments 08 and 09 are related to week 6's content.
• Week 7 is a project evaluation with no lecture class

Programming Style

• Programming style involves how you write code; a good style makes code easier to read, debug, and maintain
• Python has PEP 8 guidelines that define the standard style for Python code
• PEP-8 provides documentation for writing beautiful Python code with:
  • https://realpython.com/python-pep8/
  • https://peps.python.org/pep-0008/

Documentation

• Essential for explaining what code does, why, and how to use it
• Explanatory remarks and comments in a program serve as a guide to help others understand its structure and functionality
• Provides clarity on the purpose of specific code blocks, the logic behind certain decisions, and how different components interact with one another
• Well-written documentation ensures that code is accessible and maintainable
• Comments are ignored during execution and improve readability without affecting the program's functionality

Comments

• In Python, there are two types of comments: single-line and multi-line
• Single-line comments: begin with # and extend to the end of the line
• Single-line comments can be used multiple times to create Multi-line comment
• Multi-line comments or docstrings: use """ or ""'

Tips and Tricks for Commenting

• Begin a program with a statement of purpose and other helpful information for programmers: what the program does, key features, and unique techniques
• Accompany a variable definition with a comment that explains the variable's purpose
• Precede major segments of code with brief comments that explain their purpose
• Include comments to explain the workings of complex or tricky sections of code

Data Types in Python

• Data types define the kind of data that can be stored and manipulated in a programming language
• Everything is treated as an object, and data types specify how the interpreter should handle different types of values

Primitive Data Types

• Python has four primitive data types: integers, floats, strings, and booleans
• Integers (int): all whole numbers (e.g., 1, 0, -3)
• Floats (float): all real numbers (e.g., 7.0, -0.9, 3.142)
• Strings (str): one or more characters (e.g., "Hello world", 'Python is fun!', "56000")
• Booleans (bool): True or False

Integers

• Whole numbers without decimal places
• In real life, the range of integers is infinite
• In Python 3, the data type int is considered unbounded
• Integers are written without commas

Float

• Real numbers have infinite precision
• The digits in the fractional part can continue forever
• Python uses floating-point numbers to represent real numbers
• Python uses 64-bit floats which have 15 to 17 decimal digits of precision, but is constrained by hardware precision
• A floating-point number can be written using either ordinary decimal notation or scientific notation

Boolean

• Values can only be True or False
• Used for logical operations

Strings

• A string literal is a sequence of characters enclosed in single or double quotation marks
• "" and ''' represent the empty string
• Double-quoted strings are useful when dealing with strings that contain quotation marks or apostrophes

Escape Sequences

• An escape sequence in Python is a combination of characters that represents a special character or action
• It is typically used within strings to allow characters that would otherwise be difficult to type or display
• Escape sequences start with a backslash () followed by one or more characters
  • \b - Backspace
  • \n - Newline
  • \t - Horizontal tab
  • \ - The \ character
  • ' - Single quotation mark
  • " - Double quotation mark

String Concatenation and Repetition

• Join one or more strings using the concatenation (+) operator
• Repeat a string a given number of times using the (*) operator

Variables

• A named storage location in computer memory that holds a value
• Variables are fundamental to programming and are used to store and manipulate data

Variable Assignment

• The process of giving a variable a value using the = operator
• A variable has a name (identifier), value, and type
• Variable references use the variable name in expressions after it has been assigned: you can only refer to a variable after its assignment

Variable Naming Rules in Python

• Variable names must begin with a letter (A-Z or a-z) or an underscore (_); spaces are not allowed
• Python's variable names are case-sensitive (name and Name are different)
• Variable names can contain letters, digits (0-9), and underscores (_); the names should not start with a number or other special character
• Reserved words cannot be used as variable names
• The variable name should not be the same as the name of the saved file

Expressions in Python

• A combination of variables, values, and operators that produces a result
• Expressions can be of different types, such as arithmetic, logical, and relational

Arithmetic Expression

• Consists of numeric values, variables, and arithmetic operators that perform calculations

Integer Division

• When dividing one integer by another integer, the result will be an integer and truncate off the decimal part

Float (mixed-mode) Division

• When at least one of the operands is a float/real number, the result will be a float

Type Function

• Used to identify the data type of a value such as int, float, bool, and string

Explicit Type Conversion

• Converting from one data type to another
• int(someVariable)
• float(someVariable)

Logical Expression

• Evaluate conditions and return True or False
• These expressions are used in decision-making and looping

Logical Operators in Python

• and: returns True if both conditions are True
• or: returns True if at least one condition is True
• not: negates the Boolean value

Relational Operators

• Compare values and return True or False

Relational Operators in Python

• ==: Equal to
• !=: Not equal to
• >: Greater than
• <: Less than
• >=: Greater than or equal to
• <=: Less than or equal to

Operator Precedence

• Python follows operator precedence, meaning some operations are executed before others

Order of operator precedence

• () Parentheses - Highest
• ** Exponentiation
• Multiplication, Division, Modulus * , /, //, %
• Addition and subtraction +, -
• Comparison ==, !=, >, <, >=, <=
• Logical NOT not
• Logical AND and
• Logical OR - Lowest

This material covers Week 2 of CSC1024 Programming Principles, taught by Dr. Danish Mahmood Khan. Key information includes assessment dates for Quizzes 1 & 2 and the Final Project. Students must pass both coursework and the final project with a minimum grade of 40/100 to pass the course.