Chapter 3 Exercise Set 0: Chapter Review¶

“Being the computer”¶

Enter each of the following expressions into the Python REPL to see how Pyton evaluates it. You should anticipate what you will see before each one. When you can “be the computer” and correctly predict what you will see before you press enter, you will have learned.

```
>>> "NVCC CSC221"[5:8]
```
```
>>> type([1, 'two', 3.0][1])
```
```
>>> 'a' in 'apple'
```
```
>>> [1, 2, 3, 4, 5, 6][2:-1]
```
```
>>> type(len('Mississippi'))
```

>>> for i in 2, 4, 6, 8:
...     print(i ** 2)
...

```
>>> 3 > 2 and 1 > 2
```
```
>>> not True or False
```
```
>>> not False and True
```
```
>>> False and undefined_variable_name
```
```
>>> False or undefined_variable_name
```

What will be the Python shell’s response to the following:

>>> thing = ['a', 'b']
>>> thing.append(['c', 'd'])
>>> thing

Syntax and operations¶

What is the result of each of the following?

Add a line between each line starting with a python prompt with the value that would appear when the given expression is evaluated.

>>> 'Python'[1]
>>> "Strings are sequences of characters."[5]
>>> len("wonderful")
>>> 'Mystery'[:4]
>>> 'p' in 'Pineapple'
>>> 'apple' in 'Pineapple'
>>> 'pear' not in 'Pineapple'
>>> (2, 4, 6, 8, 10)[1:4]
>>> [("cheese", "queso"), ("red", "rojo")][1][0][2]

You’ll need to become familiar with the different methods of each type to do these.

>>> 'Python'.upper()
>>> 'Mississippi'.count('s')
>>> letters = ['c', 'z', 'b', 's']
>>> letters.sort()
>>> letters
>>> (3, 9, 8, 42, 17).index(42)
>>> "\t   \n     Don't pad me!   \n   \n".strip()
>>> mystery = 'apples pears bananas cheesedoodles'.split()
>>> mystery
>>> mystery.sort()
>>> mystery
>>> mystery.reverse()
>>> mystery

What value will appear after these two lines are entered at the prompt?

>>> word = "Pneumonoultramicroscopicsilicovolcanoconiosis"
>>> (word[6] + word[30] + word[33] + word[15]).upper()

Logical opposites¶

Give the logical opposites of these conditions
- a > b
- a >= b
- a >= 18 and day == 3
- a >= 18 and day != 3
- 3 == 3
- 3 != 3
- 3 >= 4
- not (3 < 4)

Four friends and a movie¶

Write a program in a file named movie_friends.py that will produce a session something like this:

$ python3 movie_friends.py

Hmmm... You have 5 tickets to that new movie everyone wants to see.
Whom should you invite to go with you?

Enter the name of friend one: Sean
Your invite list now contains: ['Sean']

Enter the name of friend two: Jonathan
Your invite list now contains: ['Sean', 'Jonathan']

Enter the name of friend three: Margot
Your invite list now contains: ['Sean', 'Jonathan', 'Margot']

Enter the name friend four: Justin
Your invite list now contains: ['Sean', 'Jonathan', 'Margot', 'Justin']

Great!  You are ready to go to the movie...

$

What `is` is¶

What will be the output of the following program?

this = ['I', 'am', 'not', 'a', 'crook']
that = ['I', 'am', 'not', 'a', 'crook']
print("Test 1:", this is that)
that = this
print("Test 2:", this is that)

Provide a detailed explaination of the results.

What are you learning?¶

Write a program in a file named learning_what.py that will produce a session something like this:

$ python3 learning_what.py

So, tell me one thing you are learning in that course: HTML
Your list of skills now contains: ['HTML']

Name another thing you are learning: CSS
Your list of skills now contains: ['HTML', 'CSS']

And another: Python
Your list of skills now contains: ['HTML', 'CSS', 'Python']

Wow!  I should take that class too.

$

More syntax and operations¶

How would the Python interpreter respond to each of the following if it was entered at the Python prompt?
- 'NVCC Rocks!'[5]
- "Strings are sequences of characters."[-2]
- len("What's all this then? Amen!")
- 'Mystery'[:4]
- 'x' in 'Aardvark'
- 'pin' in 'Pinapple'
- 'a' not in 'Pinapple'
- (2, 3, 5, 7, 11, 13, 17)[-3:]
- [("cheese", "red", "sing"), ("queso", "red", "cantar")][0][2][0]
You’ll need to become familiar with the different methods of each type to do these.
- 'Python'.upper()
- 'We are all in this together!'.count('e')
- (2, 3, 5, 7, 11, 13, 17, 19, 23).index(7)
- "\t \n Just the facts, mam! \n \n".strip()

What will the Python shell print out for numbers in the following shell session?

>>> numbers = [11, 7, 42, -3, 0, 18]
>>> numbers.sort()
>>> numbers

What will the Python shell print out for nomystery each time it is entered in the following shell session?

>>> nomystery = "These are the times that try men's souls".split()
>>> nomystery
>>> nomystery.sort()
>>> nomystery
>>> nomystery.reverse()
>>> nomystery