An Introduction to Interactive Programming in Python - Week one

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2020-02-22 21:15

Functions — Functions

Functions are reusable pieces of programs that take an input and produce an output.
A function definition is a compound statement consisting of a header and a body.
The header includes the keyword def, a sequence of parameters enclosed by parentheses, followed by a colon :.
The body consists of a sequence of statements, all indented by 4 spaces.
Functions may return a value using the keyword return or have a side effect (e.g., print).
To evaluate a function call, replace the function's parameters in the body of the function by their associated values in the call and execute the body of the function.
Lecture examples - Functions
More examples - Stucture of Functions, Uses of Functions, Scope of Variables, Examples of Functions

Indentation — Functions

Indentation consists of whitespace formed by blanks, tabs, and newlines.
Leading white space indicates indentation level (4 spaces per level) and specifies logical grouping of statements in Python.
Incorrect indentation can lead to errors.
Lecture examples - Functions
More examples - Function Errors

Remainders and modular arithmetic — More Operations

Standard long division yields a quotient and a remainder. The integer division operator // computes the quotient. The operator % computes the remainder.
For any integers a and b, a == b * (a // b) + (a % b).
In Python, a % b always returns an answer that is between 0 and b (even if a and/or b is negative).
Remainders and modular arithmetic are very useful in games for the purpose of "wrapping" the canvas, i.e; causing objects that pass off of one side of the canvas to reappear on the opposite side of the canvas.
Lecture examples - More operations
More examples - Modulus, Math Module,

Modules — More Operations

Modules are libraries of Python code that implement useful operations not included in basic Python.
Modules can be accessed via the import statement.
CodeSkulptor implements parts of the standard Python modules math and random.
Lecture examples - More operations
More examples - Math Module, Numbers and Strings, Random Module, Module Errors

Boolean Expressions — Logic and Comparisons

The constants True and False of the type bool.
These constants can be combined to form Boolean expressions via the logical operators and, or, and not.
The and of two Boolean expressions is True if both of the expressions are True.
The or of two Boolean expressions is True if at least one of the expressions is True.
Lecture examples - None
More examples - Booleans, Boolean Logic

Relational Operators — Logic and Comparisons

The values of two arithmetic expressions can be compared using the operators ==, !=, <, >, <=, >=.
These comparisons return either True or False .
Lecture examples - None
More examples - Comparison, Boolean Expressions

Conditional Statements — Conditionals

Conditional statements are compound statements consisting one or more clauses headed by the keywords if, elif, and else.
Each if or elif clause is followed by a Boolean expression and a colon :.
If the Boolean expression for a clause is True, the body of the clause is executed.
Lecture examples - Conditionals
More examples - if-elif-else, Examples of Conditionals