IGCSE Computer Science: Python
return
(1) the value a function will produce after it has been run — it is also a Python keyword; (2) the 'end of line' key on a keyboard, sometimes called the enter key
while loop
a kind of loop that repeats code while a comparative statement returns True
modulus
a mathematical operator that is used to return the remainder from a division calculation; e.g. 22%7 returns 1
variable
a name that refers to a place in a computer's memory where data is stored; more loosely, it can also be used to refer to that data
float
a number data-type that can have a decimal value
integer
a number data-type that cannot have a decimal value and must be a whole number
tkinter
a package of classes that are often imported in to Python programs that give methods that are useful for producing windows, drawing images and producing animations
bug
a piece of code that is causing a program to fail to run properly or at all
loop
a piece of code that keeps repeating until a certain condition is met
infinite loop
a piece of code that keeps running forever; this is usually a bad thing
function
a reusable piece of code
module
a saved python file whose functions can be used by another program
operator
a symbol that performs a simple function on some code such as multiplying two numbers or comparing them to see if they are equal; see also comparative operator and mathematical operator
default
a value given to an argument or variable as a starting point
local variable
a variable that is defined inside a function and is only usable inside that function
global variable
a variable that is usable anywhere in a program
syntax error
an error produced when a computer fails to run a program because it cannot recognise the format of the code supplied; e.g. a syntax error would be produced if a bracket had not been closed
mathematical operator
an operator that performs some mathematical function on some numbers; e.g. multiplication or addition
output
data that is sent from a program to a screen or printer, etc
data-type
different types of information stored by the computer, for example floats, integers and strings
statement
sed in this book to mean a snippet of code; strictly speaking it is a piece of code that represents a command or action; e.g. a print statement
logical operator
see comparative operator
commenting
some text in a computer program that is for the human reader and is ignored by the computer when running the program - in Python all comments begin with a hash symbol #
comparative operator
sometimes called logic operators, they allow us to compare data in a program; they include == and > (others are found in Table 3 in the Appendix)
IDLE
stands for Integrated DeveLopment Environment; this is the IDE that comes with a normal Python 3 install
IDE
stands for Integrated Development Environment; IDLE is an example of one - they are special text editors with useful tools built in for programmers
hacking
taking some previously written code and re-writing bits to make it do something different
string
text data, which can be stored in a variable
equals operator
the equals sign is used to assign a value to a variable in coding, for example n=2 assigns the value 2 to the variable n
method
the name given to a function in a class
casting
the process of converting one data-type into another; e.g. sometimes a number may stored as text but need to be converted in to an integer - this can be done like this: int ("3")
script mode
this is when we use IDLE to help us write code that we will save in a file
interactive mode
this is when we use IDLE to try out snippets of code without saving them
escape sequence
when characters that have certain meanings in Python are required in strings they have to be "escaped" so that the computer knows they do not have their usual meaning; this is done by putting a slash in front of them e.g. \ "
