ITSC 1212 Runestone Glossary

Object code

The output of the compiler after it translates the program.

Testing

The process of executing a program with various inputs to ensure it behaves as expected and correctly handles all possible scenarios.

Debugging

The process of finding and correcting errors.

Problem solving

The process of formulating a problem, finding a solution, and expressing the solution.

Immutable

The property of a sequence whose items cannot be changed.

Rules of precedence

The set of rules governing the order in which expressions involving multiple operators and operands are evaluated.

Syntax

The structure of a program.

Parse

To examine a program and analyze the syntactic structure.

Interpret

To execute a program in a high-level language by translating it one line at a time.

Concatenate

To join two operands end-to-end.

Evaluate

To simplify an expression by performing the operations in order to yield a single value.

Compile

To translate a program written in a high-level language into a low-level language all at once, in preparation for later execution.

Prompt string

Used during interactive input to provide the user with hints as to what type of value to enter.

=

= is Python's assignment token, which should not be confused with the mathematical comparison operator using the same symbol.

String (Str)

A Python data type that holds a string of characters.

Integer (Int)

A Python data type that holds positive and negative whole numbers.

Float

A Python data type which stores decimal numbers. These numbers are stored internally in two parts: a base and an exponent. When printed in the standard format, they look like decimal numbers. Beware of rounding errors when you use these, and remember that they are only approximate values.

Expression

A combination of operators and operands (variables and values) that represents a single result value. This is then evaluated to give that result.

Programming language

A formal notation for representing solutions.

Type conversion function

A function that can convert a data value from one type to another.

Print function

A function used in a program or script that causes the Python interpreter to display a value on its output device.

Algorithm

A general step by step process for solving a problem.

State snapshot

A graphical representation of a set of variables and the values to which they refer, taken at a particular instant during the program's execution.

Variable name

A name given to a variable.

Variable

A name that refers to a value.

Value

A number or string (or other things to be named later) that can be stored in a variable or computed in an expression.

Slice

A part of a string specified by a range of indices

Reference diagram

A picture showing a variable with an arrow pointing to the value (object) that the variable refers to.

Source code

A program, stored in a file, in a high-level language before being compiled or interpreted.

High-level language

A programming language like Python that is designed to be easy for humans to read and write.

Low-level language

A programming language that is designed to be easy for a computer to execute; also called machine language or assembly language.

Portability

A property of a program that can run on more than one kind of computer.

Keyword

A reserved word that is used by the compiler to parse a program; you cannot use these as variable names.

String

A sequence of characters.

Program

A sequence of instructions that specifies a computer actions and computations to be performed.

List

A sequence of values.

Data type

A set of values. (Ex. integers (int), floating-point numbers (float), and strings (str).)

Operator

A special symbol that represents a simple computation like addition, multiplication, or string concatenation.

Assignment statement

A statement that assigns a value to a name (variable).

Shell mode

A style of using Python where we type expressions at the command prompt, and the results are shown immediately.

Indexing([])

Access a single character in a string using its position (starting from 0). Example: 'This'[2] evaluates to 'i'.

Modulus operator

Also called remainder operator or integer remainder operator. Gives the remainder after performing integer division.

Semantic error

An error in a program that makes it do something other than what the programmer intended.

Syntax error

An error in a program that makes it impossible to parse (and therefore impossible to interpret).

Bug

An error in a program.

Runtime error

An error that does not occur until the program has started to execute but that prevents the program from continuing.

Exception

An error that is detected while the program is running.

Statement

An instruction that the Python interpreter can execute.

Index

An integer value used to select an item in a sequence, such as a character in a string. In Python indices start from 0.

Python shell

An interactive user interface to the Python interpreter.

Byte code

An intermediate language between source code and object code.

Integer division

An operation that divides one integer by another and yields an integer. This yields only the whole number of times that the numerator is divisible by the denominator and discards any remainder.

Sequence

An ordered collection of values where each value is identified by an integer index.

Executable

Another name for object code that is ready to be executed.

Formal language

Any one of the languages that people have designed for specific purposes, such as representing mathematical ideas or computer programs; all programming languages are formal languages.

Natural language

Any one of the languages that people speak that evolved naturally.

Decrement

Decrease by 1.

Initialization (of a variable)

Doing this action is to give a variable an initial value. Since in Python variables don't exist until they are assigned values, they are "_____" when they are created.

Increment

Increase by 1.

Comment

Information in a program that is meant for other programmers (or anyone reading the source code) and has no effect on the execution of the program.

Error messages

Notifications provided by the programming language or development environment that indicate something went wrong. They often include information about the type of error and its location in the code.

Length

Number of characters in a string. It can be found by (len) function Example: len('happy') evaluates to 5.

Token

One of the basic elements of the syntactic structure of a program, analogous to a word in a natural language.

Element

One of the values in a list (or other sequence), also called items.

Operand

One of the values on which an operator operates.

Object (Also known as a data object/ data value)

The fundamental things that programs are designed to manipulate (or that programmers ask to do things for them).

Semantics

The meaning of a program.