author：headsen chen 

date ： 2018-05-31  17:59:04

notice：本文素材来自于：<< 笨方法学python >> 这本书,由本人重新整理如下：

 

1.print的用法：

[root@localhost py]# cat print1.py #!/usr/bin/env pythonprint "Hellow world"print "Hello Again"print "I like typing this."print "This is fun."print "Yay! Printing."print "I\'d much rather you 'not'."print "I 'said' do not touch this."[root@localhost py]# /py/print1.py Hellow worldHello AgainI like typing this.This is fun.Yay! Printing.I'd much rather you 'not'.I 'said' do not touch this.

 

习题 2: 注释和井号

[root@localhost py]# cat print2.py #!/usr/bin/env python# ou bbbbbbbbbb ddddddprint "This is will run."# print 4444444444[root@localhost py]# /py/print2.py This is will run.

 

习题 3: 数字和数学计算

名字如下：

+ plus 加号

- minus 减号

/ slash 斜杠

* asterisk 星号

% percent 百分号

< less-than 小于号

> greater-than 大于号

<= less-than-equal 小于等于号

>= greater-than-equal 大于等于号

 

[root@localhost py]# cat cal.py #!/usr/bin/env pythonprint "I will now count my chickens:"print "Hens",25 + 30 /6print 'Roosters',100-25*3/4print 'Now I will count the eggs:'print 2+4+1 -4+6%2-1/4 +6print "Is it true that 3+2 < 5-7?"print 3+2 < 5-7print "What is 3+2?",3+2print "what is 5-7?",5-7print "oh,that is why it\'s False"print "How about some more."print "Is it greater?",5> -2print "Is it greater or equal?",5>=-2print "Is it less or equal?",5 <= -2

 

[root@localhost py]# python cal.py I will now count my chickens:Hens 30Roosters 82Now I will count the eggs:9Is it true that 3+2 < 5-7?FalseWhat is 3+2? 5what is 5-7? -2oh,that is why it's FalseHow about some more.Is it greater? TrueIs it greater or equal? TrueIs it less or equal? False

 

习题 4: 变量(variable)和命名

[root@localhost py]# cat var.py #!/usr/bin/env pythoncars = 100space_in_a_car = 4.0drivers = 30passengers = 90cars_not_driven = cars - driverscars_driven = driverscarpool_capacity = cars_driven * space_in_a_caraverage_passengers_per_car = passengers / cars_drivenprint "There are ",cars,"cars available."print "There are only",cars_not_driven,"empty cars today."print "We can transport",carpool_capacity,"people today."print "We have",passengers,"to carpool today."print "We need to put about",average_passengers_per_car,"in each car."[root@localhost py]# python var.py There are 100 cars available.There are only 70 empty cars today.We can transport 120.0 people today.We have 90 to carpool today.We need to put about 3 in each car.

 

习题 5: 更多的变量

[root@localhost py]# cat var2.py #!/usr/bin/env pythonmy_name = 'Zed A. Shaw'my_age = 35 # not a liemy_weight = 174 # inchesmy_height = 75 # lbsmy_eyes = 'blue'my_teech = 'white'my_hair = 'brown'print "Let\'s talk about %s." % my_nameprint "He\'s %d inches tall." % my_heightprint "He\'s %d pounds heavy." % my_weightprint "Actually that\'s not too heavy."print "He\'s got %s eyes and %s hair." %(my_eyes,my_hair)print "His teeth are usually %s depending on the coffee." % my_teech [root@localhost py]# python var2.py Let's talk about Zed A. Shaw.He's 75 inches tall.He's 174 pounds heavy.Actually that's not too heavy.He's got blue eyes and brown hair.His teeth are usually white depending on the coffee.

 

习题 6: 字符串(string)和文本

[root@localhost py]# cat string.py #!/usr/bin/env pythonx = "There are %d types of people." %10binary = 'binary'do_not = "don\'t"y = "Those who know %s and those who %s." % (binary,do_not)print xprint yprint "I said: %r." %xprint "I said: '%s'." %yjoke_evaluation = "Isn\'t that joke so funny?! %r"hilarious = Falseprint joke_evaluation % hilariousw = "This is the left side of ..."e = 'a string with right side.'print w + e

[root@localhost py]# python string.py There are 10 types of people.Those who know binary and those who don't.I said: 'There are 10 types of people.'.I said: 'Those who know binary and those who don't.'.Isn't that joke so funny?! FalseThis is the left side of ...a string with right side.

 

习题 7: 更多打印

[root@localhost py]# cat print3.py #!/usr/bin/env pythonprint "Mary had a liitle lamb."print "Its fleece was white as %s." % 'snow'print "Add everyone that Mary went."print "." * 10 # what'd that do?end1 = 'c'end2 = 'b'end3 = 'e'end4 = 'e'end5 = 's'end6 = 'e'end7 = 'B'end8 = 'u'end9 = 'r'end10 = 'g'end11 = 'e'end12 = 'r'# what that comma at the end,try removing it to see what happens.print end1 + end2 + end3+ end4 + end5 + end6print end7 +end8 +end9 +end10 + end11 +end12

[root@localhost py]# python print3.py Mary had a liitle lamb.Its fleece was white as snow.Add everyone that Mary went...........cbeeseBurger

 

习题 8: 打印

[root@localhost py]# cat print4.py #!/usr/bin/env pythonformatter = "%r %r %r %r"print formatter %(1,2,3,4)print formatter %('one','two','three','four')print formatter %(True,False,False,True)print formatter %(formatter,formatter,formatter,formatter)print formatter %("I had this thing.", "That you could type up right.","But it didn\'t sing.","So I said goodnight.")

[root@localhost py]# python print4.py 1 2 3 4'one' 'two' 'three' 'four'True False False True'%r %r %r %r' '%r %r %r %r' '%r %r %r %r' '%r %r %r %r''I had this thing.' 'That you could type up right.' "But it didn't sing." 'So I said goodnight.'

 

习题 9: 打印

[root@localhost py]# cat print5.py #!/usr/bin/env pythondays = "Mon Tue Wed Thu Fri Sat Sun"months = "Jan\nFeb\nMar\nApr\nMay\nJun\nJul\nAug"print "Here are the days: ",daysprint "Here are the months: ",monthsprint """There\'s something going on here.With the three double-quotes.We\'ll be able to type as much as we like.Even 4 lines if we want,or 5,or 6."""

[root@localhost py]# python print5.py Here are the days: Mon Tue Wed Thu Fri Sat SunHere are the months: JanFebMarAprMayJunJulAugThere's something going on here.With the three double-quotes.We'll be able to type as much as we like.Even 4 lines if we want,or 5,or 6.

 

习题10：转义和三引号用法

"I am 6'2\" tall." # 将字符串中的双引号转义

'I am 6\'2" tall.' # 将字符串种的单引号转义

 

[root@localhost py]# cat print6.py #!/usr/bin/env pythontabby_cat = "\tI\'m tabbed in."persian_cat = "I\'m split\non a line."backslash_cat = "I\'m \\ a \\ cat."fat_cat = """I\'ll do a list:\t* Cat food\t* Fishies"""print tabby_catprint persian_catprint backslash_catprint fat_cat

[root@localhost py]# python print6.py I'm tabbed in.I'm spliton a line.I'm \ a \ cat.I'll do a list:* Cat food* Fishies

 

习题 11: 提问和交互式输入

[root@localhost py]# cat input.py #!/usr/bin/env pythonprint "How old are you?",age = raw_input()print "How tall are you?",height = raw_input()print "How much do you weight?",weight = raw_input()print "So,you\'re %r old,%r tall and %r heavy."%(age,height,weight)

[root@localhost py]# python input.py How old are you? 35How tall are you? 455How much do you weight? 233So,you're '35' old,'455' tall and '233' heavy.

 

习题 12: 带提示的raw_input()

[root@localhost py]# cat input2.py #!/usr/bin/env pythonage = raw_input("How old are you? ")height = raw_input("How tall are you? ")weight = raw_input("How much do you weight? ")print "So,you\'re %r old,%r tall and %r heavy."%(age,height,weight)

[root@localhost py]# python input2.py How old are you? 34How tall are you? 544How much do you weight? 2342So,you're '34' old,'544' tall and '2342' heavy.

 

习题 13: 带参数的python文件和导入模组 ：每个参数赋予一个变量名： script, first, second

[root@localhost py]# cat argv.py #!/usr/bin/env pythonfrom sys import argvscript,first,second,third = argvprint "The script is called: ",scriptprint "Your first variable is: ",firstprint "Your second variavle is: ",secondprint "Your third variavle is: ",third

 

[root@localhost py]# python argv.py 1 2 3 The script is called: argv.pyYour first variable is: 1Your second variavle is: 2Your third variavle is: 3[root@localhost py]# python argv.py cheese apples breadThe script is called: argv.pyYour first variable is: cheeseYour second variavle is: applesYour third variavle is: bread

 

习题14 带参数的python文件2

[root@localhost py]# cat argv2.py #!/usr/bin/env pythonfrom sys import argvscript,user_name = argvprompt = '>'print "Hi %s,I\'m the %s script." %(user_name,script)print "I\'d like to ask you a few questions."print "Do you like me %s" % user_namelikes = raw_input(prompt)print "Where do you like %s?" % user_namelives = raw_input(prompt)print "What kind of computer do you have?"computer = raw_input(prompt)print """Alright,so you said %r about liking me.You live in %r. Not sure where that is.And you have a %r computer. Nice.""" %(likes,lives,computer)

 

[root@localhost py]# python argv2.py maryHi mary,I'm the argv2.py script.I'd like to ask you a few questions.Do you like me mary>noWhere do you like mary?>bikeWhat kind of computer do you have?>ausAlright,so you said 'no' about liking me.You live in 'bike'. Not sure where that is.And you have a 'aus' computer. Nice.

 

习题15: 文件的打开和读取

[root@localhost py]# cat file.py #!/usr/bin/env pythonfrom sys import argvscript,filename = argvtxt = open(filename)print "Here\' your file %r: " %filenameprint txt.read()print "Type the file name again: "file_again = raw_input(">")txt_again = open(file_again)print txt_again.read()

[root@localhost py]# python file.py ex15_sample.txt Here' your file 'ex15_sample.txt': This is stuff I typed into a file.It is really cool stuff.Lots and lots of fun to have in here.Type the file name again: >ex15_sample.txtThis is stuff I typed into a file.It is really cool stuff.Lots and lots of fun to have in here.[root@localhost py]#

 

习题 16: 读写文件

应该记住的命令如下：

close – 关闭文件。跟你编辑器的 文件->保存.. 一个意思。

read – 读取文件内容。你可以把结果赋给一个变量。

readline – 读取文本文件中的一行。

truncate – 清空文件，请小心使用该命令。

write(stuff) – 将 stuff 写入文件。

[root@localhost py]# cat file2.py #!/usr/bin/env pythonfrom sys import argvscript,filename = argvprint "We\'re going to erase %r." %filenameprint "If you don\'t want that,hit CTRL-C(^C)."print "If you do want that,hit RETURN."raw_input("?")print "Openning the file ..."target = open(filename,'w')print "Truncating the file.Goodby!"target.truncate()print "Now I\'m going to ask you for three lines."line1 = raw_input("line 1: ")line2 = raw_input("line 2: ")line3 = raw_input("line 3: ")print "I\'m going to write these to the file."target.write(line1)target.write("\n")target.write(line2)target.write("\n")target.write(line3)target.write("\n")print "And finally,we close it."target.close()

 

运行该脚本：随便取个文件名：bb.txt

[root@localhost py]# python file2.py bb.txt We're going to erase 'bb.txt'.If you don't want that,hit CTRL-C(^C).If you do want that,hit RETURN.?Openning the file ...Truncating the file.Goodby!Now I'm going to ask you for three lines.line 1: 1111111111line 2: 2222222222line 3: 3333333333I'm going to write these to the file.And finally,we close it.

检验：新生成的bb.txt的文件内容是否为写入的内容

[root@localhost py]# cat bb.txt 111111111122222222223333333333