OLI Course Flashcards
What is computation?
a sequence of steps that can be executed by a computer
What is a computer’s instruction set?
The primitive instructions a computer knows how to execute
What is the SYNTAX of a programming language?
rules that determine what expressions are well-formed
What are semantics of a programming language?
associating meaning with expressions (?)
A LOW-LEVEL programming language is ____
closer to the instruction set of the computer
A HIGH-LEVEL programming language is closer to ___
natural language of humans
What is an interpreter?
a special program that converts high-level programming language instructions into low-level ones that can be executed by the computer
An interpreter combines what 2 phases?
- translation to machine language
- execution
What is imperative programming?
computation is described by a sequence of commands that change the state of data objects
What data type represents real numbers?
FLOAT
What data type contains a number with decimals?
FLOAT
How is the type STRING represented in Python?
single OR double quotes (use double for better transfer to other languages)
What type is returned by i / j (division) in Python?
ALWAYS A FLOAT
What is meant by 100 // 50 in Python - what is it called, and what does it return?
integer (floor) division
returns 2 - the quotient as an integer, ignoring any remainder
What is 50 // 100 in Python?
0 - the integer quotient, ignoring any remainder
What is data type and value is 3e4 in Python?
FLOAT! 30000.0
Why does -15//10 evaluate to -2 in Python?
In Python, floor division rounds DOWN to a lesser-value integer.
How is Boolean false represented in Python?
False
What is the assignment symbol in Python?
=
For example, x = 10 means that the value 10 is assigned to the variable named x
What is the syntax for string concatenation?
+
“Susan” + “ “ + “Klefstad”
What does the * do when used with a string?
concatenates int n copies of the string
What is the difference between an expression and a statement?
an expression denotes a value, or evalutates operators to return a value
a statement is a command or instruction (like assignment) that changes the state of the computer (memory)
What keyword is used to define a function?
def
def function_name (list of formal parameters):
function body
What is the difference between parameters and arguments?
parameters are used in function definition, while arguments are the actual values bound during execution
What syntax is required for a function body?
It must be indented
What is the syntax for a comment in Python?
#
A return statement can only be used where?
in the body of a function definition
What are the syntax rules for indentation of a function body?
must be indented, any amount (customary 4 spaces), but all the SAME amount
If there is no explicit value returned by a function, what does it return?
the special value called None
What does -15//10 evaluate to in Python?
-2
because integer/floor division in Python always rounds down to a lesser number
What does 15//10 evaluate to in Python?
1
because 1.5 rounds DOWN to the lesser integer
What is a module in Python?
a file containing related definitions and statements, ending in .py and can be imported (without the .py)
In Python, what does the function range(4) do?
creates a sequence of 4 integers, 0 1 2 3
