Appendix H — Assignment 3

H.1 (1) Suppose spam contains the list [‘a’, ‘b’, ‘c’, ‘d’]. What does spam[int(int('3' * 2) // 11)] evaluate to?

1. ‘a’
   
2. ‘b’
   
3. ‘c’
   
4. ‘d’

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H.2 (2) Suppose bacon contains the list [3.14, ‘Sherry’, 18, ‘Sherry’, True]. What does bacon.append(100) make to the list value in bacon look like?

1. [100, 3.14, ‘Sherry’, 18, ‘Sherry’, True]
   
2. [3.14, ‘Sherry’, 18, ‘Sherry’, True]
   
3. [3.14, ‘Sherry’, 18, ‘Sherry’, True, 100]
   
4. None of above

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H.3 (3) How would you assign the value 'hello' as the third value in a list stored in a variable named computer?

1. computer[3] <- ‘hello’
   
2. computer[3] == ‘hello’
   
3. computer[2] = ‘hello’
   
4. computer[2] == ‘hello’

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H.4 (4) What is []?

1. dictionary
   
2. tuple
   
3. list
   
4. dataframe

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H.5 (5) What are the operators for list concatenation and list replication?

1. -, /
   
2. +, **
   
3. +, *
   
4. -, //

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H.6 (6) What are two ways to remove values from a list?

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The del statement and the remove() list method are two ways to remove values from a list.

H.7 (7) What is the difference between lists and tuples?

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Lists are mutable; they can have values added, removed, or changed. Tuples are immutable; they cannot be changed at all. Also, tuples are written using parentheses, ( ), while lists use the square brackets, [ ].

H.8 (8) What is the difference between copy.copy() and copy.deepcopy()?

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The copy.copy() function will do a shallow copy of a list, while the copy.deepcopy() function will do a deep copy of a list.
That is, only copy.deepcopy() will duplicate any lists inside the list.

H.9 (9) Write a function takes a list value as an argument and returns a string with all the items separated by comma and a space, with and inserted before the last item.

sample output:
If you enter a list ['Mathematics', 'computer', programming'], then you should get Mathematics, computer, and programming.

def list_to_string(spam):
    """
    Parameters
    ----------
    spam: list
        The input list.
    Returns
    -------
    string: str
        The ouput string.
    """
    # coding your answer here
    string = ""
    for i in range(len(spam)):
        if i != len(spam) - 1:
            string = string + spam[i] + ", "
        else:
            string = string + "and " + spam[i]
    return(string)

H.10 (10) Say you have a list of lists, grid, where each value in the inner lists is a one-character string. Copy the grid value and write code that uses it to print the image.

grid = [['.', '.', '.', '.', '.', '.'],
        ['.', 'O', 'O', '.', '.', '.'],
        ['O', 'O', 'O', 'O', '.', '.'],
        ['O', 'O', 'O', 'O', 'O', '.'],
        ['.', 'O', 'O', 'O', 'O', 'O'],
        ['O', 'O', 'O', 'O', 'O', '.'],
        ['O', 'O', 'O', 'O', '.', '.'],
        ['.', 'O', 'O', '.', '.', '.'],
        ['.', '.', '.', '.', '.', '.']]

sample output

. . 00 . 00 . .   
. 0000000 .   
. 0000000 .   
. . 00000 . .   
. . . 000 . . .   
. . . . 0 . . . .

Hint:
In order to print the image, you will need to use a loop in a loop.

# coding your answer here
for i in range(len(grid[0])):
    string = ""
    for j in range(len(grid)):
        string = string + grid[j][i]
    print(string)