Variables and Expressions

Question 1

What is a variable?

Answer 1

a named item, such as x or num_people, that holds a value.

Question 2

What is incrementation?

Answer 2

A statement that causes a variable’s value to increase.

Question 3

What is an identifier?

Answer 3

The name of a variable.

Question 4

What are the rules for identifers?

Answer 4

Cannot start with a number. Cannot contain special characters other than underscore. Cannot be a reserved word.

Question 5

What is an object?

Answer 5

Any item in Python.

Question 6

What is name binding?

Answer 6

The process of associating names with interpreter objects.

Question 7

What is garbage collection?

Answer 7

The process of deleting unnecessary objects.

Question 8

What are the properties of objects?

Answer 8

Value, Type and Identity.

Question 9

What is id()?

Answer 9

A function that returns the memory address an object is stored at.

Question 10

What is type()?

Answer 10

A function that returns the type of an object

Question 11

Are strings mutable?

Answer 11

No.

Question 12

Are integers mutable?

Answer 12

No.

Question 13

What is Overflow?

Answer 13

An error that occurs when a value is too large to be stored in the memory allocated by the interpreter.

Question 14

What are the minimum and maximum floating point values?

Answer 14

Min: 2.3 x 10^-308, Max: 1.8 x 10^308

Question 15

How do you manipulate significant figures in Python?

Answer 15

Use print(f’{}’). Put variable:.xf inside the curly brackets with x indicating the desired decimal place.

Question 16

What is an expression?

Answer 16

A combination of items that evaluates to a value.

Question 17

What is the order of precedence?

Answer 17

Parentheses, exponent, unary - (negative), multiplication = division = modulo, addition = subtraction, left-to-right.

Question 18

What are compound operators?

Answer 18

A method of incrementing a variable. Syntax is an arithmetic operator in front of an equals sign.

Question 19

What is floor division?

Answer 19

A form of division that rounds the quotient down to the nearest whole number.

Question 20

What is modulo?

Answer 20

A form of division that returns the remainder.

Question 21

How does Python distinguish between modules and scritps?

Answer 21

Scripts have the line “if __name__ == ‘__main__’”.

Question 22

How do you access objects from a model after it’s imported?

Answer 22

By using dot notation. module.variable.

Question 23

What is a function?

Answer 23

A list of statements that can be executed by referring to the function’s name.

Question 24

What is an argument?

Answer 24

An item that is passed to a function.

Question 25

What is randrange(x)?

Answer 25

A function that returns a random number from 0 to x -1.

Question 26

What is randint(x)?

Answer 26

A function that returns a random number from 0 to x.

Question 27

What is random.seed()?

Answer 27

A function that determines the initial value that all random functions draw from. By default, random functions draw from the system clock.

Question 28

What is Unicode?

Answer 28

A list of numbers that each represent one character.

Question 29

What is a code point in Unicode?

Answer 29

The term for the numbers in Unicode.

Question 30

What are Escape sequences?

Answer 30

A method of modifying a string from inside the string. They start with a backslash.

Question 31

What is a raw string.

Answer 31

A kind of string that ignores escape sequences. The syntax is r’text’.

Question 32

What is ord()?

Answer 32

A function that returns the encode integer value of a one character string.