# CS8—Midterm 1 PRACTICE EXAM #1E01, 09M, Phill Conrad, UC Santa Barbara 08/17/2009

Name: ________________________________________________________

This exam is closed book, closed notes, closed mouth, cell phone off,
except for:

• You are permitted one sheet of paper (max size 8.5x11") on which to write notes
• These sheets will be collected with the exam, and might not be returned

There are 100 points worth of questions on the exam, and you have 85 minutes to complete the exam.

A hint for allocating your time—on your first pass through the exam:

• if a question is worth 10 points, spend no more than 5 minutes on it
• if a question is worth 20 points, spend no more than 10 minutes on it
• if a question is worth 40 points, spend no more than 20 minutes on it
• etc.

If you do that, you'll complete your first pass thorugh the exam in 50 minutes, and still have 35 minutes to

• revisit any questions where you need more time

1. (20 pts) Write a Python function definition that takes the radius and height of a cone as parameters, and returns the volume of that cone. The formula for volume of a cone, in math notation, is v =1/3πr2h. You may use `math.pi` as the value of pi. You may assume that the statement `import math` has already been included in the Python source file.

2. (20 pts) Write a Python function definition for a function called theLongerOne that takes two parameters, each of which is a string. Return the longer of the two strings. If the strings are of equal length, return the first one passed into the function—for example theLongerOne('dog', 'cat') should return 'dog'

Your function should pass these test cases:

```check_expect("theLongerOne test 1",theLongerOne('mouse','cat'),'mouse') check_expect("theLongerOne test 2",theLongerOne('mouse','chicken'),'chicken') check_expect("theLongerOne test 3",theLongerOne('cat','dog'),'cat') ```
3. (30 pts) Fill in the table below, according to these instructions:
• The first column describes a Python expression
• In the second column, fill in a Python expression that matches the description in the first column
• In the third column, fill in the value of the expression you put in the second column. If that expression involves variables, put the values you assumed for those variables in the fourth column.
• The first row is filled in as an example.
Description
Expression
Value
values you assumed for variables (if any)

An expression involving the addition operator, one variable, and one int value

x + 1
3
x=2

An expression involving the ** operator

An expression involving an operator, where the final expressiong has a value of type string

An expression of type bool (Boolean)

An expression involving the multiplication operator, one variable,
and where the result is of type float

An expression involving one addition operator and one multiplication operator

4. (15 pts) Listed below is an session from IDLE, showing interaction between a user and the Python shell. The response from the shell at various points has been replaced with blanks. Fill in the blanks with what the Python shell would print.

Remember that variables retain their previous values.

If the blanks are too small, you can write your answers beside them.
```>>> x = 3
>>> y = 7
>>> x * 5

_______
>>> y / 5

_______
>>> y / 7

_______
>>> y / 8

_______
>>> x + 2 * y
_______
>>> x + y

_______
>>> x = x + 2
>>> x

_______
>>> x + y

_______
>>> y

_______
>>> x

_______
>>> "x"

_______
>>> "y" + "x"

_______
>>> "y" * 3

_______
>>> x * 2

________
>>> x ** 2

________
>>> ```
5. (10 pts) Suppose your friend is taking CS8, and says:

I'm still not 100% clear on the difference between a function call and a function definition. I understand how they look different on the page—I mean, the function defintion has the word `def` in it, duh—and the function call doesn't. But I'm not sure I understand what they mean. Can you explain it?

How do you explain the difference to your friend in plain english?

6. (5 pts) Which of the following are legal variable names in Python? For each, circle yes or no:

 `lunch_break` Circle:       yes        no `onceAnd4All` Circle:       yes        no `twice bitten` Circle:       yes        no `3timesALady` Circle:       yes        no `def` Circle:       yes        no `my-friend` Circle:       yes        no

Total points: ?