十一、标题党生成器

原文：http://inventwithpython.com/bigbookpython/project11.html

我们的网站需要欺骗人们去看广告！但是想出有创意的原创内容太难了。幸运的是，有了标题党生成器，我们可以让一台计算机产生数百万个令人发指的虚假标题。都是低质量的，但读者似乎并不介意。这个程序根据你的需要从一个 MadLibs 风格的模板中生成尽可能多的标题。

这个程序中有很多标题模板的文本，但是代码本身很简单，适合初学者。

运行示例

当您运行clickbait.py时，输出将如下所示：

Clickbait Headline Generator
By Al Sweigart email@protectedOur website needs to trick people into looking at ads!
Enter the number of clickbait headlines to generate:
> 1000
Big Companies Hate Him! See How This New York Cat Invented a Cheaper Robot
What Telephone Psychics Don't Want You To Know About Avocados
You Won't Believe What This North Carolina Shovel Found in Her Workplace
`--snip--`
14 Reasons Why Parents Are More Interesting Than You Think (Number 1 Will Surprise You!)
What Robots Don't Want You To Know About Cats
This Florida Telephone Psychic Didn't Think Robots Would Take Her Job. She Was Wrong.

工作原理

这个程序有几个函数来生成不同类型的标题党。他们每个人都从STATES、NOUNS、PLACES、WHEN和其他列表中获得随机单词。这些函数然后用format()字符串方法将这些单词插入到一个模板字符串中，然后返回这个字符串。这就像一本“Mad Libs”活动书，只是电脑会填空，让程序在几秒钟内生成数千个标题党。

"""Clickbait Headline Generator, by Al Sweigart email@protected
A clickbait headline generator for your soulless content farm website.
This code is available at https://nostarch.com/big-book-small-python-programming
Tags: large, beginner, humor, word"""import random# Set up the constants:
OBJECT_PRONOUNS = ['Her', 'Him', 'Them']
POSSESIVE_PRONOUNS = ['Her', 'His', 'Their']
PERSONAL_PRONOUNS = ['She', 'He', 'They']
STATES = ['California', 'Texas', 'Florida', 'New York', 'Pennsylvania','Illinois', 'Ohio', 'Georgia', 'North Carolina', 'Michigan']
NOUNS = ['Athlete', 'Clown', 'Shovel', 'Paleo Diet', 'Doctor', 'Parent','Cat', 'Dog', 'Chicken', 'Robot', 'Video Game', 'Avocado','Plastic Straw','Serial Killer', 'Telephone Psychic']
PLACES = ['House', 'Attic', 'Bank Deposit Box', 'School', 'Basement','Workplace', 'Donut Shop', 'Apocalypse Bunker']
WHEN = ['Soon', 'This Year', 'Later Today', 'RIGHT NOW', 'Next Week']def main():print('Clickbait Headline Generator')print('By Al Sweigart email@protected')print()print('Our website needs to trick people into looking at ads!')while True:print('Enter the number of clickbait headlines to generate:')response = input('> ')if not response.isdecimal():print('Please enter a number.')else:numberOfHeadlines = int(response)break  # Exit the loop once a valid number is entered.for i in range(numberOfHeadlines):clickbaitType = random.randint(1, 8)if clickbaitType == 1:headline = generateAreMillenialsKillingHeadline()elif clickbaitType == 2:headline = generateWhatYouDontKnowHeadline()elif clickbaitType == 3:headline = generateBigCompaniesHateHerHeadline()elif clickbaitType == 4:headline = generateYouWontBelieveHeadline()elif clickbaitType == 5:headline = generateDontWantYouToKnowHeadline()elif clickbaitType == 6:headline = generateGiftIdeaHeadline()elif clickbaitType == 7:headline = generateReasonsWhyHeadline()elif clickbaitType == 8:headline = generateJobAutomatedHeadline()print(headline)print()website = random.choice(['wobsite', 'blag', 'Facebuuk', 'Googles','Facesbook', 'Tweedie', 'Pastagram'])when = random.choice(WHEN).lower()print('Post these to our', website, when, 'or you\\'re fired!')# Each of these functions returns a different type of headline:
def generateAreMillenialsKillingHeadline():noun = random.choice(NOUNS)return 'Are Millenials Killing the {} Industry?'.format(noun)def generateWhatYouDontKnowHeadline():noun = random.choice(NOUNS)pluralNoun = random.choice(NOUNS) + 's'when = random.choice(WHEN)return 'Without This {}, {} Could Kill You {}'.format(noun, pluralNoun, when)def generateBigCompaniesHateHerHeadline():pronoun = random.choice(OBJECT_PRONOUNS)state = random.choice(STATES)noun1 = random.choice(NOUNS)noun2 = random.choice(NOUNS)return 'Big Companies Hate {}! See How This {}  {} Invented a Cheaper {}'.format(pronoun, state, noun1, noun2)def generateYouWontBelieveHeadline():state = random.choice(STATES)noun = random.choice(NOUNS)pronoun = random.choice(POSSESIVE_PRONOUNS)place = random.choice(PLACES)return 'You Won\\'t Believe What This {}  {} Found in {}  {}'.format(state, noun, pronoun, place)def generateDontWantYouToKnowHeadline():pluralNoun1 = random.choice(NOUNS) + 's'pluralNoun2 = random.choice(NOUNS) + 's'return 'What {} Don\\'t Want You To Know About {}'.format(pluralNoun1, pluralNoun2)def generateGiftIdeaHeadline():number = random.randint(7, 15)noun = random.choice(NOUNS)state = random.choice(STATES)return '{} Gift Ideas to Give Your {} From {}'.format(number, noun, state)def generateReasonsWhyHeadline():number1 = random.randint(3, 19)pluralNoun = random.choice(NOUNS) + 's'# number2 should be no larger than number1:number2 = random.randint(1, number1)return '{} Reasons Why {} Are More Interesting Than You Think (Number {} Will Surprise You!)'.format(number1, pluralNoun, number2)def generateJobAutomatedHeadline():state = random.choice(STATES)noun = random.choice(NOUNS)i = random.randint(0, 2)pronoun1 = POSSESIVE_PRONOUNS[i]pronoun2 = PERSONAL_PRONOUNS[i]if pronoun1 == 'Their':return 'This {}  {} Didn\\'t Think Robots Would Take {} Job. {} Were Wrong.'.format(state, noun, pronoun1, pronoun2)else:return 'This {}  {} Didn\\'t Think Robots Would Take {} Job. {} Was Wrong.'.format(state, noun, pronoun1, pronoun2)# If the program is run (instead of imported), run the game:
if __name__ == '__main__':main() 

在输入源代码并运行几次之后，尝试对其进行实验性的修改。你也可以自己想办法做到以下几点：

• 添加其他类型的标题党。
• 添加新的单词类别，超出NOUNS、STATES等。

探索程序

试着找出下列问题的答案。尝试对代码进行一些修改，然后重新运行程序，看看这些修改有什么影响。

1. 如果删除或注释掉第 34 行的numberOfHeadlines = int(response),会得到什么错误信息？
2. 如果将第 34 行的int(response)改为response，会得到什么错误信息？
3. 如果将第 19 行改为WHEN = []，会得到什么错误信息？

十二、柯拉茨序列

原文：http://inventwithpython.com/bigbookpython/project12.html

柯拉茨序列，也称为3n + 1问题，是最简单的不可能数学问题。（不过不用担心，程序本身对初学者来说已经足够简单了。）从一个起始数字，n，遵循三个规则得到序列中的下一个数字：

1. 如果n是偶数，那么下一个数字n就是n / 2。
2. 如果n是奇数，那么下一个数n就是n * 3 + 1。
3. 如果n为 1，则停止。否则，重复。

一般认为，但迄今为止没有数学证明，每个起始数最终终止于 1。关于柯拉茨序列的更多信息可以在en.wikipedia.org/wiki/Collatz_conjecture找到。

运行示例

当您运行collatz.py时，输出将如下所示：

Collatz Sequence, or, the 3n + 1 Problem
By Al Sweigart email@protectedThe Collatz sequence is a sequence of numbers produced from a starting
number n, following three rules:
`--snip--`
Enter a starting number (greater than 0) or QUIT:
> 26
26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1Collatz Sequence, or, the 3n + 1 Problem
By Al Sweigart email@protected
`--snip--`
Enter a starting number (greater than 0) or QUIT:
> 27
27, 82, 41, 124, 62, 31, 94, 47, 142, 71, 214, 107, 322, 161, 484, 242, 121, 364, 182, 91, 274, 137, 412, 206, 103, 310, 155, 466, 233, 700, 350, 175, 526, 263, 790, 395, 1186, 593, 1780, 890, 445, 1336, 668, 334, 167, 502, 251, 754, 377, 1132, 566, 283, 850, 425, 1276, 638, 319, 958, 479, 1438, 719, 2158, 1079, 3238, 1619, 4858, 2429, 7288, 3644, 1822, 911, 2734, 1367, 4102, 2051, 6154, 3077, 9232, 4616, 2308, 1154, 577, 1732, 866, 433, 1300, 650, 325, 976, 488, 244, 122, 61, 184, 92, 46, 23, 70, 35, 106, 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2, 1

工作原理

模数运算符可以帮助您确定一个数字是偶数还是奇数。记住这个操作符是一种“余数”操作符。23 除以 7 是 3 余 2，而23 mod 7只是 2。偶数除以 2 没有余数，奇数除以 2 有余数 1。当n为偶数时，第 33 行if n % 2 == 0:中的条件求值为True。当n为奇数时，计算结果为False。

"""Collatz Sequence, by Al Sweigart email@protected
Generates numbers for the Collatz sequence, given a starting number.
More info at: https://en.wikipedia.org/wiki/Collatz_conjecture
This code is available at https://nostarch.com/big-book-small-python-programming
Tags: tiny, beginner, math"""import sys, timeprint('''Collatz Sequence, or, the 3n + 1 Problem
By Al Sweigart email@protectedThe Collatz sequence is a sequence of numbers produced from a starting
number n, following three rules:1) If n is even, the next number n is n / 2.
2) If n is odd, the next number n is n * 3 + 1.
3) If n is 1, stop. Otherwise, repeat.It is generally thought, but so far not mathematically proven, that
every starting number eventually terminates at 1.
''')print('Enter a starting number (greater than 0) or QUIT:')
response = input('> ')if not response.isdecimal() or response == '0':print('You must enter an integer greater than 0.')sys.exit()n = int(response)
print(n, end='', flush=True)
while n != 1:if n % 2 == 0:  # If n is even...n = n // 2else:  # Otherwise, n is odd...n = 3 * n + 1print(', ' + str(n), end='', flush=True)time.sleep(0.1)
print() 

探索程序

试着找出下列问题的答案。尝试对代码进行一些修改，然后重新运行程序，看看这些修改有什么影响。

1. 以 32 开头的柯拉茨序列中有多少个数字？
2. 以 33 开头的柯拉茨序列中有多少个数字？
3. 起始数为 2 的幂（2、4、8、16、32、64、128 等等）的排序序列是否总是只由偶数组成（除了最后的 1）？
4. 输入0作为起始整数会发生什么？

#13 康威的生命游戏

原文：http://inventwithpython.com/bigbookpython/project13.html

康威的生命游戏是一种细胞自动机模拟，它遵循简单的规则来创建有趣的模式。它是由数学家约翰·康威在 1970 年发明的，并由马丁·加德纳在《科学美国人》的“数学游戏”专栏推广开来。今天，它是程序员和计算机科学家的最爱，尽管它更像是一个有趣的可视化而不是真正的“游戏”二维棋盘有一个“单元格”网格，每个单元格都遵循三个简单的规则：

• 具有两个或三个邻居的活细胞在模拟的下一步中保持存活。
• 在模拟的下一步中，正好有三个邻居的死细胞变成活的。
• 在模拟的下一步中，任何其他细胞死亡或保持死亡。

下一步模拟中细胞的活或死状态完全取决于它们的当前状态。这些细胞不会“记住”任何旧的状态。关于这些简单规则产生的模式，有大量的研究。不幸的是，康威教授于 2020 年 4 月因并发症在新冠肺炎去世。更多关于康威《生命的游戏》的信息可以在en.wikipedia.org/wiki/Conway%27s_Game_of_Life找到，更多关于马丁·加德纳的信息可以在en.wikipedia.org/wiki/Martin_Gardner找到。

运行示例

当您运行conwaysgameoflife.py时，输出将如下所示：

 O                  O                 OO      O  O
O     O    O  O                 O                      O OOOO          O OO
OO    O   O                     O          O            O              O O
OO        O    O                          OO                        OO
OO        OO                             O O    O                    OOOO    O O                    O  OOOOO                          OO    OO                       OO    OOOO             O                     O OOO             OO OO             OO  OOOO               OO          OOOO    O  OO     OO                O O       O  OO  OO O   O    OOO  O                 O    O          O   OO O    O  OOOO                     OOOO  OO       OO   O    OOOOO O
OO            O                      O   OOO     O OOO        OOOO       O

工作原理

单元的状态存储在字典中的cells和nextCells变量中。两个字典都有键的(x, y)元组（其中x和y是整数），活细胞的'O'，死细胞的' '。第 40 到 44 行被设置为将这些字典的表示打印到屏幕上。cells变量的字典表示单元的当前状态，而nextCells存储模拟下一步中单元的字典。

"""Conway's Game of Life, by Al Sweigart email@protected
The classic cellular automata simulation. Press Ctrl-C to stop.
More info at: https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life
This code is available at https://nostarch.com/big-book-small-python-programming
Tags: short, artistic, simulation"""import copy, random, sys, time# Set up the constants:
WIDTH = 79   # The width of the cell grid.
HEIGHT = 20  # The height of the cell grid.# (!) Try changing ALIVE to '#' or another character:
ALIVE = 'O'  # The character representing a living cell.
# (!) Try changing DEAD to '.' or another character:
DEAD = ' '   # The character representing a dead cell.# (!) Try changing ALIVE to '|' and DEAD to '-'.# The cells and nextCells are dictionaries for the state of the game.
# Their keys are (x, y) tuples and their values are one of the ALIVE
# or DEAD values.
nextCells = {}
# Put random dead and alive cells into nextCells:
for x in range(WIDTH):  # Loop over every possible column.for y in range(HEIGHT):  # Loop over every possible row.# 50/50 chance for starting cells being alive or dead.if random.randint(0, 1) == 0:nextCells[(x, y)] = ALIVE  # Add a living cell.else:nextCells[(x, y)] = DEAD  # Add a dead cell.while True:  # Main program loop.# Each iteration of this loop is a step of the simulation.print('\\n' * 50)  # Separate each step with newlines.cells = copy.deepcopy(nextCells)# Print cells on the screen:for y in range(HEIGHT):for x in range(WIDTH):print(cells[(x, y)], end='')  # Print the # or space.print()  # Print a newline at the end of the row.print('Press Ctrl-C to quit.')# Calculate the next step's cells based on current step's cells:for x in range(WIDTH):for y in range(HEIGHT):# Get the neighboring coordinates of (x, y), even if they# wrap around the edge:left  = (x - 1) % WIDTHright = (x + 1) % WIDTHabove = (y - 1) % HEIGHTbelow = (y + 1) % HEIGHT# Count the number of living neighbors:numNeighbors = 0if cells[(left, above)] == ALIVE:numNeighbors += 1  # Top-left neighbor is alive.if cells[(x, above)] == ALIVE:numNeighbors += 1  # Top neighbor is alive.if cells[(right, above)] == ALIVE:numNeighbors += 1  # Top-right neighbor is alive.if cells[(left, y)] == ALIVE:numNeighbors += 1  # Left neighbor is alive.if cells[(right, y)] == ALIVE:numNeighbors += 1  # Right neighbor is alive.if cells[(left, below)] == ALIVE:numNeighbors += 1  # Bottom-left neighbor is alive.if cells[(x, below)] == ALIVE:numNeighbors += 1  # Bottom neighbor is alive.if cells[(right, below)] == ALIVE:numNeighbors += 1  # Bottom-right neighbor is alive.# Set cell based on Conway's Game of Life rules:if cells[(x, y)] == ALIVE and (numNeighbors == 2or numNeighbors == 3):# Living cells with 2 or 3 neighbors stay alive:nextCells[(x, y)] = ALIVEelif cells[(x, y)] == DEAD and numNeighbors == 3:# Dead cells with 3 neighbors become alive:nextCells[(x, y)] = ALIVEelse:# Everything else dies or stays dead:nextCells[(x, y)] = DEADtry:time.sleep(1)  # Add a 1 second pause to reduce flickering.except KeyboardInterrupt:print("Conway's Game of Life")print('By Al Sweigart email@protected')sys.exit()  # When Ctrl-C is pressed, end the program. 

在输入源代码并运行几次之后，尝试对其进行实验性的修改。标有(!)的注释对你可以做的小改变有建议。你也可以自己想办法做到以下几点：

• 调整开始为活细胞的百分比，而不是总是使用 50%。
• 添加从文本文件中读取初始状态的功能，这样用户可以手动编辑起始单元格状态。

探索程序

试着找出下列问题的答案。尝试对代码进行一些修改，然后重新运行程序，看看这些修改有什么影响。

1. 把 10 行的WIDTH = 79改成WIDTH = 7会怎么样？
2. 如果删除或注释掉第 36 行的print('\\n' * 50)会发生什么？
3. 如果把第 28 行的random.randint(0, 1)改成random.randint(0, 10)会怎么样？
4. 如果把第 85 行的nextCells[(x, y)] = DEAD改成nextCells[(x, y)] = ALIVE会怎么样？

十四、倒计时

原文：http://inventwithpython.com/bigbookpython/project14.html

这个程序显示一个数字计时器，倒计时到零。第六十四个项目的sevseg.py模块“七段显示模块”为每个数字生成图形，而不是直接呈现数字字符。您必须先创建这个文件，倒计时程序才能运行。然后，将倒计时设置为你喜欢的任何秒数、分钟数和小时数。这个程序类似于项目 19，“数字钟。”

运行示例

当您运行countdown.py时，输出将如下所示：

 __   __       __   __       __   __
|  | |  |  *  |  | |  |  *   __| |__|
|__| |__|  *  |__| |__|  *  |__   __|Press Ctrl-C to quit.

工作原理

运行import sevseg之后，您可以调用sevseg.getSevSegStr()函数来获得一个包含七个段数字的多行字符串。然而，倒计时程序需要在时、分、秒之间显示一个由星号组成的冒号。这需要用splitlines()方法将这些数字的三行多行字符串分割成三个单独的字符串。

"""Countdown, by Al Sweigart email@protected
Show a countdown timer animation using a seven-segment display.
Press Ctrl-C to stop.
More info at https://en.wikipedia.org/wiki/Seven-segment_display
Requires sevseg.py to be in the same folder.
This code is available at https://nostarch.com/big-book-small-python-programming
Tags: tiny, artistic"""import sys, time
import sevseg  # Imports our sevseg.py program.# (!) Change this to any number of seconds:
secondsLeft = 30try:while True:  # Main program loop.# Clear the screen by printing several newlines:print('\\n' * 60)# Get the hours/minutes/seconds from secondsLeft:# For example: 7265 is 2 hours, 1 minute, 5 seconds.# So 7265 // 3600 is 2 hours:hours = str(secondsLeft // 3600)# And 7265 % 3600 is 65, and 65 // 60 is 1 minute:minutes = str((secondsLeft % 3600) // 60)# And 7265 % 60 is 5 seconds:seconds = str(secondsLeft % 60)# Get the digit strings from the sevseg module:hDigits = sevseg.getSevSegStr(hours, 2)hTopRow, hMiddleRow, hBottomRow = hDigits.splitlines()mDigits = sevseg.getSevSegStr(minutes, 2)mTopRow, mMiddleRow, mBottomRow = mDigits.splitlines()sDigits = sevseg.getSevSegStr(seconds, 2)sTopRow, sMiddleRow, sBottomRow = sDigits.splitlines()# Display the digits:print(hTopRow    + '     ' + mTopRow    + '     ' + sTopRow)print(hMiddleRow + '  *  ' + mMiddleRow + '  *  ' + sMiddleRow)print(hBottomRow + '  *  ' + mBottomRow + '  *  ' + sBottomRow)if secondsLeft == 0:print()print('    * * * * BOOM * * * *')breakprint()print('Press Ctrl-C to quit.')time.sleep(1)  # Insert a one-second pause.secondsLeft -= 1
except KeyboardInterrupt:print('Countdown, by Al Sweigart email@protected')sys.exit()  # When Ctrl-C is pressed, end the program.) 

在输入源代码并运行几次之后，尝试对其进行实验性的修改。你也可以自己想办法做到以下几点：

• 提示用户输入开始倒计时的时间。
• 让用户输入在倒计时结束时显示的消息。

探索程序

试着找出下列问题的答案。尝试对代码进行一些修改，然后重新运行程序，看看这些修改有什么影响。

1. 如果把第 13 行的secondsLeft = 30改成secondsLeft = 30.5会怎么样？
2. 如果把第 30、33、36 行的2改成1会怎么样？
3. 如果把 52 行的time.sleep(1)改成time.sleep(0.1)会怎么样？
4. 如果把 53 行的secondsLeft -= 1改成secondsLeft -= 2会怎么样？
5. 如果删除或注释掉第 18 行的print('\\n' * 60)会发生什么？
6. 如果删除或注释掉第 10 行的import sevseg,会得到什么错误信息？

十五、深坑

原文：http://inventwithpython.com/bigbookpython/project15.html

这个节目是一个永远深入地下的深洞的动画。虽然很短，但这个程序利用了计算机屏幕的滚动特性，产生了一个有趣且无休止的可视化效果，证明了制作有趣的东西并不需要太多代码。这个项目类似于 58 项目“彩虹”

运行示例

当您运行deepcave.py时，输出如下：

Deep Cave, by Al Sweigart email@protected
Press Ctrl-C to stop.
##          #
##         ##
##          #
##          #
          
#          ##
          
##          #
#          ##
`--snip--`

工作原理

这个程序利用了这样一个事实，即打印新行最终会导致前面的行在屏幕上上移。通过在每行上打印一个稍微不同的间隙，程序创建了一个滚动动画，看起来好像观众在向下移动。

左侧的井号字符数由leftWidth变量跟踪。中间的空格数由gapWidth变量跟踪。右侧标签字符的数量从WIDTH - gapWidth - leftWidth开始计算。这确保了每一行总是相同的宽度。

"""Deep Cave, by Al Sweigart email@protected
An animation of a deep cave that goes forever into the earth.
This code is available at https://nostarch.com/big-book-small-python-programming
Tags: tiny, beginner, scrolling, artistic"""import random, sys, time# Set up the constants:
WIDTH = 70  # (!) Try changing this to 10 or 30.
PAUSE_AMOUNT = 0.05  # (!) Try changing this to 0 or 1.0.print('Deep Cave, by Al Sweigart email@protected')
print('Press Ctrl-C to stop.')
time.sleep(2)leftWidth = 20
gapWidth = 10while True:# Display the tunnel segment:rightWidth = WIDTH - gapWidth - leftWidthprint(('#' * leftWidth) + (' ' * gapWidth) + ('#' * rightWidth))# Check for Ctrl-C press during the brief pause:try:time.sleep(PAUSE_AMOUNT)except KeyboardInterrupt:sys.exit()  # When Ctrl-C is pressed, end the program.# Adjust the left side width:diceRoll = random.randint(1, 6)if diceRoll == 1 and leftWidth > 1:leftWidth = leftWidth - 1  # Decrease left side width.elif diceRoll == 2 and leftWidth + gapWidth < WIDTH - 1:leftWidth = leftWidth + 1  # Increase left side width.else:pass  # Do nothing; no change in left side width.# Adjust the gap width:# (!) Try uncommenting out all of the following code:#diceRoll = random.randint(1, 6)#if diceRoll == 1 and gapWidth > 1:#    gapWidth = gapWidth - 1  # Decrease gap width.#elif diceRoll == 2 and leftWidth + gapWidth < WIDTH - 1:#    gapWidth = gapWidth + 1  # Increase gap width.#else:#    pass  # Do nothing; no change in gap width. 

在输入源代码并运行几次之后，尝试对其进行实验性的修改。标有(!)的注释对你可以做的小改变有建议。

探索程序

试着找出下列问题的答案。尝试对代码进行一些修改，然后重新运行程序，看看这些修改有什么影响。

1. 如果把第 23 行的(' ' * gapWidth)改成('.' * gapWidth)会怎么样？
2. 如果把第 32 行的random.randint(1, 6)改成random.randint(1, 1)会怎么样？
3. 如果把第 32 行的random.randint(1, 6)改成random.randint(2, 2)会怎么样？
4. 如果删除或注释掉第 17 行的leftWidth = 20,会得到什么错误信息？
5. 如果把第 10 行的WIDTH = 70改成WIDTH = -70会怎么样？
6. 如果将第 11 行的PAUSE_AMOUNT = 0.05改为PAUSE_AMOUNT = -0.05，会得到什么错误信息？