27、

<pre>
print(not False)
print(not True)
print(True or False)
print(True or True)
print(False or True)
print(False or False)
print(True and False)
print(True and True)
print(False and True)
print(False and False)
print(not (True or False))
print(not (True or True))
print(not (False or True))
print(not (False or False))
print(not (True and False))
print(not (True and True))
print(not (False and True))
print(1 != 0)
print(1 != 1)
print(0 != 1)
print(0 != 0)
print(1 == 0)
print(1 == 1)
print(0 == 1)
print(0 == 0)
輸出：
True
False
True
True
True
False
False
True
False
False
False
False
False
True
True
False
True
True
False
True
False
False
True
False
True
</pre>

28矿筝、

<pre>
print(True and True)
print(False and True)
print(1 == 1 and 2 == 1)
print("test" == "test")
print(1 == 1 or 2 != 1)
print(True and 1 == 1)
print(False and 0 != 0)
print(True or 1 == 1)
print("test" == "testing")
print(1 != 0 and 2 == 1)
print("test" != "testing")
print("test" == 1)
print(not (True and False))
print(not (1 == 1 and 0 != 1))
print(not (10 == 1 or 1000 == 1000))
print(not (1 != 10 or 3 == 4))
print(not ("testing" == "testing" and "Zed" == "Cool Guy"))
print(1 == 1 and not ("testing" == 1 or 1 == 0))
print("chunky" == "bacon" and not (3 == 4 or 3 == 3))
print(3 == 3 and not ("testing" == "testing" or "Python" == "Fun"))
輸出：
True
False
False
True
True
True
False
True
False
False
True
False
True
False
False
False
True
True
False
False
</pre>

<pre>
思考題：

運算符 >,<,<=,>=

</pre>

29隙畜、

<pre>
people = 20
cats = 30
dogs = 15
if people < cats: #如果people小于cats
print("too many cats! the world is doomed!")
if people > cats: #如果people大于cats
print("not many cats! the world is saved!")
if people < dogs: #如果people小于dogs
print("the world is drooled on!")
if people > dogs: #如果people大于dogs
print("the world is dry!")
dogs += 5 #dogs每輪增加5
if people >= dogs: #peoples大于等于dogs
print("people are greater than or equal to dogs.")
if people <= dogs: #peoples小于等于dogs
print("people are less than or equal to dogs.")
if people == dogs: #peoples等于dogs
print("people are dogs.")

這里因為沒寫明dogs小于peoples會發(fā)生什么侠讯。所以在后面就會停止。

輸出：
too many cats! the world is doomed!
the world is dry!
people are greater than or equal to dogs.
people are less than or equal to dogs.
people are dogs.
</pre>

<pre>
思考題：

不縮進(jìn)最楷，程序之間的運行邏輯就會亂。只要是true的結(jié)果都會運行黑界。改掉后管嬉。如果if的判斷不是true，就不會有返回了朗鸠。

</pre>

30蚯撩、

<pre>
people = 30
cars = 40
buses = 15
if cars > people: #cars的值大于people
print("We should take the cars.")
elif cars < people:#cars的值小于people
print("We should not take the cars.")
else: #其他情況
print("We can't decide.")
if buses > cars:#buses大于cars
print("That's too many buses.")
elif buses < cars: #buses小于cars
print("Maybe we could take the buses.")
else: #其他情況
print("We still can't decide.")
if people > buses: #people的值大于buses
print("Alright, let's just take the buses.")
else: #其他情況
print("Fine, let's stay home then.")
輸出：
We should take the cars.
Maybe we could take the buses.
Alright, let's just take the buses.

</pre>

<pre>
思考題：
注釋見上面
else是只所有的其他情況，elif是要有具體的情況判斷語句的烛占。
</pre>

31胎挎、

<pre>

31

print("you enter a dark room with two doors. do you go through door #1 or door #2?")
door = input("> ")
if door == "1":
print("there's a giant bear here eating a cheese cake. what do you do?")
print("1.take the cake.")
print("2.scream at the bear.")
bear = input("> ")
if bear == "1":
print("the bear eats your face off. good job!")
elif bear == "2":
print("the bear eats your legs off. good job!")
else:
print("well,doing %s is probably better. bear runsaway." % bear)
elif door == "2":
print("you stare into the endless abyss at cthulhu's retina.")
print("1.blueberries.")
print("2.yellow jacket clothespins.")
print("3.understanding revolvers yelling melodies.")
insanity = input("> ")
if insanity == "1" or insanity == "2":
print("your body survives powered by a mind of jello.good job!")
else:
print("the insanity rots your eyes into a pool of muck.good job")
else:
print("you stumble around and fall on a knife and die.good job")
輸出：
you enter a dark room with two doors. do you go through door #1 or door #2?

1
there's a giant bear here eating a cheese cake. what do you do?
1.take the cake.
2.scream at the bear.
2
the bear eats your legs off. good job!

</pre>

<pre>
思考題：
這游戲設(shè)計頭疼沟启。
</pre>

32、

<pre>
the_count = [1,2,3,4,5]
fruits = ["apples","oranges","pears","apricots"]
change = [1,"pennies",2,"dimes",3,"quarters"]

this first kind of for-loop goes through a list

for number in the_count:
print("this is count %d" % number)

same as above

for fruit in fruits:
print("a fruit of type: %s" % fruit)

also we can go through mixed lists too

notice we have to use %r since we don't know what's in it

for i in change:
print("i got %r" % i)

we can also build lists, first start with an empty one

element = []

then use the range function tu do 0 to 5 counts

for i in range(0,6):
print("adding %d to the list." % i)
#append is a function that lists understand
element.append(i)

now we can print them out too

for i in element:
print("element was:%d" % i )
輸出：
this is count 1
this is count 2
this is count 3
this is count 4
this is count 5
a fruit of type: apples
a fruit of type: oranges
a fruit of type: pears
a fruit of type: apricots
i got 1
i got 'pennies'
i got 2
i got 'dimes'
i got 3
i got 'quarters'
adding 0 to the list.
adding 1 to the list.
adding 2 to the list.
adding 3 to the list.
adding 4 to the list.
adding 5 to the list.
element was:0
element was:1
element was:2
element was:3
element was:4
element was:5
</pre>

<pre>
思考題：
在第 22 行犹菇，你可不可以直接將 elements 賦值為 range(0,6)德迹，而無需使用 for 循環(huán)？ 不可以揭芍。胳搞。
在 Python 文檔中找到關(guān)于列表的內(nèi)容，仔細(xì)閱讀以下称杨，除了 append 以外列表還支持哪些操作肌毅？
http://www.jb51.net/article/47978.htm
</pre>

33、

<pre>
i = 0
number = []
while i < 6:
print("at the top i is %d" % i )
number.append(i)
i = i + 1
print("numbers now:" , number)
print("at the bottom i is %d" % i)
print("the numbers:")
for num in number:
print(num)

輸出：
at the top i is 0
numbers now: [0]
at the bottom i is 1
at the top i is 1
numbers now: [0, 1]
at the bottom i is 2
at the top i is 2
numbers now: [0, 1, 2]
at the bottom i is 3
at the top i is 3
numbers now: [0, 1, 2, 3]
at the bottom i is 4
at the top i is 4
numbers now: [0, 1, 2, 3, 4]
at the bottom i is 5
at the top i is 5
numbers now: [0, 1, 2, 3, 4, 5]
at the bottom i is 6
the numbers:
0
1
2
3
4
5
</pre>

<pre>
思考題：

函數(shù)暫時不會姑原。

接下來使用 for-loop 和 range 把這個腳本再寫一遍悬而。你還需要中間的加值操作嗎？如果你不去掉它锭汛，會有什么樣的結(jié)果笨奠？

</pre>

34、

<pre>
animals = ["bear","tiger","penguin","zebra"]
bear = animals[1]
print(bear)

記住: ordinal == 有序唤殴，以 1 開始般婆；cardinal == 隨機(jī)選取, 以 0 開始。

輸出：tiger
</pre>

<pre>
思考題：
無
</pre>