BSAN 310 Programming

Key Words

Predefined words used to write program in high level language. Each key word has specific meaning (e.g. import, if, for)

Operators

Perform operations on data. Ex: Math operators to perform arithmetic.

Syntax

Set of rules to be followed when writing program.

Statement

Individual instruction used in high-level language.

Variable

Name that represents a value stored in the computer memory. Used to access and manipulate data stored in memory. A variable references the value it represents.

Assignment statement

Used to create a variable make it reference data. General format is variable = expression. Ex: age = 29.

Condition

The if statement, Python syntax: if condition then result.

The if-else statement

Dual alternative decision structure: two possible paths of execution. One is taken if the condition is true, the other if false.

If-elif-else statement

Simpler to write, can include many. If condition, statements, elif, else.

The While Loop: Condition-Controlled

While: While condition is true, do something.

The While Loop Parts

Two Parts:

• Conditions tested for true or false value

• Statements repeated as long as condition is true

While Loop Format

General Format:

While condition:

         statements

In flow chart, line goes back to previous part

The For Loop: A count-Controlled Loop

Iterates a specific number of times. Designed to work with sequence of data items. Iterates once for each item in the sequence.

For Loop Format

for variable in [val1, val2, etc]:
statements

Target Variable

The variable which is the target of the assignment at the beginning of each iteration

Funtion

Group of statements within a program that perform as specific task. Usually one task of a large program.

Can be executed in order to perform overall program task. Known as divide and conquer approach.

Function definition

Specifies what function does

def function_name():

statement

statement

Function header

First line of function. Includes keyword def and function name, followed by parentheses and colon.

Block

Set of statements that belong together as a group. Ex: the statements included in a function

Argument

Piece of data that is sent into a function. Function can use argument in calculations. When calling the function, the argument is placed in parentheses following the function name.

Lists

An object that contains multiple data items. Anything with brackets.

Element

An item in a list

Format of List

list = [item1, item2, etc.]

Print function

Can be used to display an entire list

Tuple

An immutable sequence. Once it is created it cannot be changed.

Tuple Format

tuple_name = (item1, item2)

Tuples support operations as lists

• Subscript indexing for retrieving elements

• Methods such as index

• Built in functions such as len, min, max

• Slicing expressions

• The in, +, and * operators

Dictionary

Object that stores a collection of data. Each element consists of a key and a value. To retrieve a specific value, use the key associated with it

Key and value

Often referred to as mapping of key to value. Key must be an immutable object

Dictionary Format

dictionary =

                {key1:val1, key2:val2}

Set

Object that stores a collection of data in same way as mathematical set

Set Requirements

All items must be unique. Set is unordered. Elements can be of different data types. For empty set, call set().