Ch 2 Simple Python Data

Question 1

assignment token

Answer 1

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

Question 2

comment

Answer 2

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

Question 3

data type

Answer 3

a set of values. the type of a value determines how it can be used in expressions. so far, the types you have seen are integers (int), floating-point number (float), and strings (str)

Question 4

decrement

Answer 4

decrease by 1

Question 5

evaluate

Answer 5

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

Question 6

expression

Answer 6

a combination of operators and operands (variables and values) that represents a single result value. Expressions are evaluated to give that result.

Question 7

float

Answer 7

A Python data type which store floating-point numbers. Floating-point 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 sue floats and remember that they are only approximate values.

Question 8

increment

Answer 8

Both as a noun and as a verb, increment means to increase by 1

Question 9

initialization (of a variable)

Answer 9

To initialize a variable is to give it an initial value. Since in Python variables don’t exist until they are assigned values, they are initialized when they are created. In other programming languages this is not the case, and variables can be created without being initialized, in which case they have either default or garbage values

Question 10

int

Answer 10

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

Question 11

integer division

Answer 11

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

Question 12

keyword

Answer 12

A reserved word that is used by the compiler to parse program; you cannot use keywords ( like if, def, and while) as variable names

Question 13

modus operator

Answer 13

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

Question 14

object

Answer 14

Also known as a data object (or data value). The fundamental things that programs are designed to manipulate (or that programmers ask to do things for them).

Question 15

operand

Answer 15

One of the values on which an operator operates.

Question 16

operator

Answer 16

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

Question 17

prompt string

Answer 17

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

Question 18

reference diagram

Answer 18

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

Question 19

rules of precedence

Answer 19

the set of rules governing the order in which expressions involving multiple operators and operands are evaluated. PEMDAS. 1 parentheses, 2 exponentiation, 3 multiplication and division, 4 additions and subtraction. Those operators that share a level (like multiplication and division) execute from left to right. So 6 * 9 / 7 would execute as (6 * 9) / 7. Exponentiation is read from right to left. So 4 ** 2 ** 3 would be 2 ** 3 and then 4 ** 8.

Question 20

state snapshot

Answer 20

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.

Question 21

statement

Answer 21

An instruction that the Python interpreter can execute. So far we have only seen the assignment statement, but we will soon meet the import statement and the for statement, i.e., a statement is anything and everything that makes up one line of Python code

Question 22

str

Answer 22

A Python data type that holds a string of characters.

Question 23

type conversion function

Answer 23

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

Question 24

value

Answer 24

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

Question 25

variable

Answer 25

A name that refers to a value

Question 26

variable name

Answer 26

A name given to a variable.