2. Variables, Expressions, and Statements

Question 1

assignment

Answer 1

A statement that assigns a value to a variable.

Question 2

concatenate

Answer 2

To join two operands end to end.

Question 3

comment

Answer 3

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 4

evaluate

Answer 4

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

Question 5

expression

Answer 5

A combination of variables, operators, and values that represents a single result value.

Question 6

floating point

Answer 6

A type that represents numbers with fractional parts.

Question 7

integer

Answer 7

A type that represents whole numbers.

Question 8

keyword

Answer 8

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

Question 9

mnemonic

Answer 9

A memory aid. We often give variables mnemonic names to help us remember what is stored in the variable.

Question 10

modulus operator

Answer 10

An operator, denoted with a percent sign (%), that works on integers and yields the remainder when one number is divided by another.

Question 11

operand

Answer 11

One of the values on which an operator operates.

Question 12

operator

Answer 12

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

Question 13

rule of precedence

Answer 13

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

Question 14

statement

Answer 14

A section of code that represents a command or action. So far, the statements we have seen are assignments and print expression statement.

Question 15

string

Answer 15

A type that represents sequences of characters.

Question 16

type

Answer 16

A category of values. The types we have seen so far are integers (type int), floating-point numbers (type float), and strings (type str).

Question 17

value

Answer 17

One of the basic units of data, like a number or string, that a program manipulates.

Question 18

variable

Answer 18

A name that refers to a value.

Question 19

Write a program that uses input to prompt a user for their name and then welcomes them.

Enter your name: Chuck
Hello Chuck

Answer 19

1. question = ‘Enter your Name : ‘
2. name = input(question)
3. print(‘Hello’,name)

Question 20

Write a program to prompt the user for jours and rate per hour to compute gross pay.

Enter Hours: 35
Enter Rate: 2.75
Pay: 96.25

We won’t worry about making sure our pay has exactly two digits after the decimal place for now. If you want, you can play with the built-in Python round function to properly round the resulting pay to two decimal places.

Answer 20

hours = int(input(‘Enter Hours: ‘))
rate = float(input(‘Enter Rate: ‘))
gross_pay = hours * rate
print(‘Pay:’,gross_pay)

Question 21

Assume that we execute the following assignment statements:

width = 17
height = 12.0

For each of the following expressions, write the value of the expression and the type (of the value of the expression).

1. width//2
2. width/2.0
3. height/3
4. 1 + 2 * 5

Use the Python interpreter to check your answers.

Answer 21

1. width = 17
2. height = 12.0
3. print(width//2)
4. print(width/2.0)
5. print(height/3)
6. print(1 + 2 * 5)

Question 22

Write a program which prompts the user for a Celsius temperature, convert the temperature to Fahrenheit, and print out the converted temperature.

Answer 22

1. Celsius = float(input(‘Enter Celsius temperature: ‘))
2. Fahrenheit = ((Celsius * 9) / 5) + 32
3. print(‘Fahrenheit:’,Fahrenheit)