Module 2.1 Introduction to Python 3

Programming Basics

Computer Program

Set of instructions executing sequentially

Input

A program takes in data from a file, keyboard, touchscreen, network, etc. for computation

Process

A program performs computations on input data, such as adding two values like x+y

Output

A program puts that data somewhere, such as to a file, screen, or network

Variables

Containers that store values that vary as programs are able to update these containers with new values

Flowchart

A graphical language for creating or viewing computer programs and how they operate

Statements

In a program, there is a list of statements that carries out some action and is executed sequentially

Interpreter

A computer program that directly executes (runs) instructions (statements) written in a program

Character

Any letter (a-z, A-Z), digit (0-9), space, or symbol (~,!,@,etc.)

String literal

Text characters within double quotes (“this is a string”)

Newline

Special two-character sequence \n whose appearance in an output string literal causes the cursor to move to the next output line

Pseudocode

Text that resembles a program in a real programming language, but is simplified to human understanding

Integrated Development Environment (IDE)

Environment where code development is done

Scripting Languages

Languages that allow programs to execute without the need for compilation

Script

A program whose instructions are executed by another program called an interpreter

Python

A scripting language created by Guido Van Rossum that was designed for simplicity and readability, while providing as much power and flexibility as other scripting languages like Perl

open-source language

the community of users participate in defining the language and creating new interpreters

Python Interpreter

A computer program that executes code written in the Python programming language

Interactive Interpreter

A program that allows the user to execute one line of code at a time

Code

Textual representation of a program

Line

Row of text

Prompt

The statement “>>>” is displayed by the interactive interpreter to indicate code is ready to be processed

Expressions

code that returns a value when some computation is performed using variables

Assignment

storing a value to a variable using “=”

print()

function that displays variables or expression values

Comments

statements used to explain portions of code to a human reader

Syntax Error - definition

An error made when violating a programming language’s rules in implemented statements that are combined to create a program

Syntax Error - occurance

The interpreter will create a message when encountering a syntax error, that will report the line number where the issue is located, and provides the programmer information as to what type of error is occurring

Runtime Errors

A program’s syntax may be correct, but the program attempts an impossible operations, such as dividing by zero or multiplying strings together

Crash

A runtime error stops the execution of the program and the abrupt termination of a program

Logic Error

A part of the written program is logically flawed and results in bugs, which is a logic error that occurs when the desired output of the program differs from the actual output of the program

Indentation Error

The lines of the program are not properly indented

Value Error

An invalid value is used

Name Error

The program tries to use a variable that does not exist

Type Error

An operation uses incorrect types

A logic error is often called a bug

True

The Python interpreter is a computer program that executes code written in the Python programming language.

True

The input obtained by input() is any text that a user typed, including numbers, letters, or special characters like # or @. Such text in a computer program is called a string.

True

Programs commonly get input values, then perform some processing on that input and then put output values to a screen or elsewhere.

True

Expressions

__________ are code that return a value when evaluated; for example, the code wage * hours * weeks is an expression that computes a number. The symbol * is used for multiplication.

Whitespace

Any space, tab, or newline is called __________________.

Variable

In Python, a new __________ is created by performing an assignment using the = symbol, such as salary = wage * hours * weeks.

Text in string literals may have letters, numbers, spaces, or symbols like @ or #.

True

Syntax errors are found before the program is ever run by the interpreter.

True

Programming is largely about problem solving: Creating a methodical solution to a given task.

True

Print()

the __________ function displays variables or expression values.

Type

Strings and integers are each an example of a __________, which determines how a value can behave.

Compared to flowcharts, pseudocode may be easier to create (just by typing) and to share than graphics.

True

String Literal

Text enclosed in quotes is known as a(n)

Most coding activities strictly require a student program's output to exactly match the expected output, including whitespace.

True

A program can have variables, each being a name that can hold a value, like a variable x holding the value 7.

True

The interpreter will generate a message when encountering a syntax error.

True

In Python, the value of a variable can be printed out via: 

print(variable_name) (without quotes).

True

Algorithm

A sequence of instructions that solves a problem is called a(n)

input()

In Python, reading input is achieved using the __________ function.

In Python, a programmer can add end=' ' inside of print() to keep the output of a subsequent print statement on the same line separated by a single space. Ex: print('Hello', end=' ')

True

Just because the program loads and executes does not mean that the program is correct.

True

In Python, each call to print() generally outputs on a new line.

True

Adding a string inside the parentheses of input() displays a prompt to the user before waiting for input and is a useful shortcut to adding an additional print statement line.

True