Day5

• 习题  24:  更多练习

1 print("Let's practice everything.") 2 print('You\'d need to know \'bout escapes with \\ that do \n newlines and \t tabs.') 3  4 poem = """ 5 \tThe lovely world 6 with logic so firmly planted 7 cannot discern \n the needs of love 8 nor comprehend passion from intuition 9 and requires an explanation10 \n\twhere there is none.11 """12 13 print("-------------")14 print(poem)15 print("-------------")16 17 five = 10 - 2 + 3 - 618 print("This should be five: %s" % five)19 20 def secret_formula(started):21     jelly_beans = started * 50022     jars = jelly_beans / 100023     crates = jars / 10024     return jelly_beans, jars, crates25 26 start_point = 1000027 beans,jars,crates = secret_formula(start_point)28 29 print("With a starting point of: %d" % start_point)30 print("We'd have %d beans, %d jars, and %d crates." % (beans,jars,crates))31 32 start_point = start_point / 1033 34 print("We can also do that this way:")35 print("We'd have %d beans, %d jars, and %d crates." % (secret_formula(start_point)))

Let's practice everything.

You'd need to know 'bout escapes with \ that do

newlines and tabs.

-------------

The lovely world

with logic so firmly planted

cannot discern

the needs of love

nor comprehend passion from intuition

and requires an explanation

where there is none.

-------------

This should be five: 5

With a starting point of: 10000

We'd have 5000000 beans, 5000 jars, and 50 crates.

We can also do that this way:

We'd have 500000 beans, 500 jars, and 5 crates.

• 习题  25:  更多更多的练习

1 def break_words(stuff): 2     """This function will break up words for us""" 3     words = stuff.split(' ') 4     return words 5  6 def sort_words(words): 7     """Sorts the words.""" 8     return sorted(words) 9 10 def print_first_word(words):11     """Prints the first word after popping it off."""12     word = words.pop(0)13     print(word)14 15 def print_last_word(words):16     """Prints the last word after popping it off."""17     word = words.pop(-1)18     print(word)19 20 def sort_sentence(sentence):21     """Takes in a full sentence and returns the sorted words."""22     words = break_words(sentence)23     return sort_words(words)24 25 def print_first_and_last(sentence):26     """Prints the first and last words of the sentence."""27     words = break_words(sentence)28     print_first_word(words)29     print_last_word(words)30 31 def print_first_and_last_sorted(sentence):32     """Sorts the words then prints the first and last one."""33     words = sort_sentence(sentence)34     print_first_word(words)35     print_last_word(words)

1 Python 3.6.3 (v3.6.3:2c5fed8, Oct  3 2017, 18:11:49) [MSC v.1900 64 bit (AMD64)] on win32 2 Type "copyright", "credits" or "license()" for more information. 3 >>> import day525 4 >>> sentence = "All good things come to those who wait." 5 >>> words = day525.break_words(sentence) 6 >>> words 7 ['All', 'good', 'things', 'come', 'to', 'those', 'who', 'wait.'] 8 >>> sorted_words = day525.sort_words(words) 9 >>> sorted_words10 ['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']11 >>> day525.print_first_word(words)12 All13 >>> day525.print_last_word(words)14 wait.15 >>> wrods16 Traceback (most recent call last):17   File "
     
      ", line 1, in 
      
       18     wrods19 NameError: name 'wrods' is not defined20 >>> words21 ['good', 'things', 'come', 'to', 'those', 'who']22 >>> day525.print_first_word(sorted_words)23 All24 >>> day525.print_last_word(sorted_words)25 who26 >>> sorted_words27 ['come', 'good', 'things', 'those', 'to', 'wait.']28 >>> sorted_words = day525.sort_sentence(sentence)29 >>> sorted_Words30 Traceback (most recent call last):31   File "
       
        ", line 1, in 
        
         32     sorted_Words33 NameError: name 'sorted_Words' is not defined34 >>> sorted_words35 ['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']36 >>> day525.print_first_and_last(sentence)37 All38 wait.39 >>> day525.print_first_and_last_sorted(sentence)40 All41 who
        
       
      
     

直接在pycharm中运行，导入自定义模块day525

1 import sys 2 sys.path.append("E:\py\learnpythonthehardway\Day5") 3 import day525 4 sentence = "All good things come to those who wait." 5 words = day525.break_words(sentence) 6 print(words) 7 sorted_words = day525.sort_words(words) 8 print(sorted_words) 9 10 day525.print_first_word(words)11 day525.print_last_word(words)12 13 print(words)

要先加一个路径 sys.path.append("  ")

结果：

['All', 'good', 'things', 'come', 'to', 'those', 'who', 'wait.']

['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']

All

wait.

['good', 'things', 'come', 'to', 'those', 'who']

• 习题  26:  恭喜你，现在可以考试了！

http://learnpythonthehardway.org/exercise26.txt

• 习题  27:  记住逻辑关系

and 与

or 或

not 非

 

 != (not equal) 不等于

 == (equal) 等于

 >= (greater-than-equal) 大于等于

 <= (less-than-equal) 小于等于

 True 真

 False 假

• 习题  28:  布尔表达式练习

1 a=True and True 2 b=False and True 3 c=1 == 1 and 2 == 1 4 d="test" == "test" 5 e=1 == 1 or 2 != 1 6 f=True and 1 == 1 7 g=False and 0 != 0 8 h=True or 1 == 1 9 i="test" == "testing"10 j= 1 != 0 and 2 == 111 12 print(a,b,c,d,e,f,g,h,i,j)

True False False True True True False True False False

• 习题  29:  如果(if)

1 people = 20 2 cats = 30 3 dogs = 15 4  5 if people < cats: 6     print("Too many cats! The world is doomed!") 7  8 if people > cats: 9     print("Not many cats! The world is saved!")10 11 if people < dogs:12     print("The world is dry!")13 14 dogs +=515 16 if people >= dogs:17     print("People are greater than or equal to dogs.")18 19 if people <= dogs:20     print("People are less than or equal to dogs.")21 22 if people == dogs:23     print("People are dogs.")

结果：

1 Too many cats! The world is doomed!2 People are greater than or equal to dogs.3 People are less than or equal to dogs.4 People are dogs.

• 习题  30: Else  和  If

1 people = 20 2 cars = 30 3 buses = 30 4  5 if cars > people: 6     print("We should take the cars.") 7 elif cars < people: 8     print("We should not take the cars.") 9 else:10     print("We can't decide.")11 12 if buses > cars:13     print("That's too many buses.")14 elif buses < cars:15     print("Maybe we could take the buses.")16 else:17     print("We still can't decide.")18 19 if people > buses:20     print("Alright, let's just take the buses.")21 else:22     print("Fine, let's stay home then.")

结果：

We should take the cars.

We still can't decide.

Fine, let's stay home then.

• 习题  31:  作出决定

1 print("You enter a dark room with two doors. Do you go through door #1 or door #2?") 2  3 door = input("> ") 4  5 if door == "1": 6     print("There's a giant bear here eating a cheese cake. What do you do?") 7     print("1. Take the cake.") 8     print("2. Scream at the bear.") 9 10     bear = input("> ")11 12     if bear == "1":13         print("The bear eats your face off. Good job!")14     elif bear == "2":15         print("The bear eats your legs off. Good job!")16     else:17         print("Well, doing %s is probably better.Bear runs away." % bear)18 elif door == "2":19     print("You stare into the endless abyss at Cthulhu's retina.")20     print("1.Blueberries.")21     print("2.Yellow jacket clothespins.")22     print("3.Understanding revolvers yelling melodies.")23 24     insanity = input("> ")25 26     if insanity == "1" or insanity == "2":27         print("Your body survives powered by a mind of jello. Good job!")28     else:29         print("The insanity rots your eyes into a pool of muck. Good job!")30 31 else:32     print("You stumble around and fall on a knife and die. Good job!")

结果：

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.

> 3

Well, doing 3 is probably better.Bear runs away.

• 习题  32:  循环和列表

1 the_count = [ 1, 2, 3, 4 , 5] 2 fruits = ['apples', 'oranges', 'pears', 'apricots'] 3 change = [1, 'pennies', 2, 'dimes', 3, 'quarters'] 4  5 #this first kind of for-loop goes through a list 6 for number in the_count: 7     print("This is count %d" % number) 8  9 #same as above10 for fruit in fruits:11     print("A fruit of type: %s" % fruit)12 13 #also we can go through mixed lists too14 #notice we have to use %r since we don't know what's in it15 for i in change:16     print("I got %r" % i)17 18 #we can also build lists, first start with an empty one19 elements = []20 21 #then use the range function to do 0 to 5 counts22 for i in range(0,6):23     print("Adding %d to the list." % i)24     #append is a function tha lists understand25     elements.append(i)26 27 #now we can print them out too28 for i in elements:29     print("Element was: %d" % i)

结果

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

python3 注意：

elements=list(range(0,6,2))print(elements)print(range(0,6,2))[0, 2, 4]range(0, 6, 2)

python3使用range是一个生成器，

python2使用range是一个列表，

python2使用xrange是一个生成器。

要得到列表应该 list（range（x,y,z））

• 习题  33: While  循环

1 i = 0 2 numbers = list() 3  4 while i < 6: 5     print("At the top i is %d" % i) 6     numbers.append(i) 7     i+=1 8     print("Numbers now:",numbers) 9     print("At the bottom i is %d" % i)10 11 print("The numbers:")12 13 for num in numbers:14     print(num)

结果：

At the top i is 0Numbers now: [0]At the bottom i is 1At the top i is 1Numbers now: [0, 1]At the bottom i is 2At the top i is 2Numbers now: [0, 1, 2]At the bottom i is 3At the top i is 3Numbers now: [0, 1, 2, 3]At the bottom i is 4At the top i is 4Numbers now: [0, 1, 2, 3, 4]At the bottom i is 5At the top i is 5Numbers now: [0, 1, 2, 3, 4, 5]At the bottom i is 6The numbers:012345

加分题：

先定义

1 def kl(b):2     """创建一个从零到 b-1 的列表 间隔为 1 """3     i = 04     numbers = list()5 6     while i < b:7         numbers.append(i)8         i += 19     return numbers

执行：

1 import sys2 sys.path.append("E:\py\learnpythonthehardway\Day5")3 import d533extra4 x=d533extra.kl(6)5 print(x)

结果：

[0, 1, 2, 3, 4, 5]

• 习题  34:  访问列表的元素

1 animals = ['bear', 'tiger', 'penguin', 'zebra']2 bear = animals[0]3 tiger = animals[1]4 penguin = animals[2]5 zebra = animals[3]6 7 print("\n",bear,"\n",tiger,"\n",penguin,"\n",zebra)

bear

tiger

penguin

zebra

• 习题  35:  分支和函数

1 from sys import exit 2  3 def gold_room(): 4     print("This room is full of gold. How much do you take?") 5     dead=print("Man, learn to type a number.") 6     dead2=print() 7     next1=input("> ") 8     if "0" in next1 or "1" in next1: 9         how_much = int(next1)10         if how_much < 50:11             print("Nice, you're not greedy, you win!")12             exit(0)13         else:14             dead215     else:16         dead17 18 def bear_room():19     print("There is a bear here.")20     print("The bear has a bunch of honey.")21     print("The fat bear is in front of another door.")22     print("How are you going to move the bear?")23     bear_moved = False24 25     while True:26         next1 = input("> ")27 28         if next1 == "take honey":29             print("The bear looks at you then slaps your face off.")30         elif next1 == "taunt bear" and not bear_moved:31             print("The bear has moved from the door.You can go through it now.")32             bear_moved=True33         elif next1 == "taunt bear" and bear_moved:34             print("The bear gets pissed off and chews your leg off.")35         elif next1 == "open the door" and bear_moved:36             gold_room()37         else:38             print("I got no idea what that means.")39 40 def cthulhu_room():41     print("Here you see the great evil Cthulhu.")42     print("He, it, whatever stares at you and you go insane.")43     print("Do you flee for your life or eat your head.")44 45     next1=input("> ")46 47     if "flee" in next1:48         start()49     elif"head"in next1:50         print("Well that was tasty!")51     else:52         cthulhu_room()53 54 def start():55     print("You are in a dark room.")56     print("There is a door to your right and left.")57     print("Which one do you take?")58 59     next1=input("> ")60 61     if next1 == "left":62         bear_room()63     elif next1 =="right":64         cthulhu_room()65     else:66         print("You stumble around the room until you strave.")67 68 start()

结果

You are in a dark room.There is a door to your right and left.Which one do you take?> leftThere is a bear here.The bear has a bunch of honey.The fat bear is in front of another door.How are you going to move the bear?> taunt bearThe bear has moved from the door.You can go through it now.> open the doorThis room is full of gold. How much do you take?Man, learn to type a number.> 0Nice, you're not greedy, you win!