2.笨方法学python（习题6-9）-蒲公英云

2.笨方法学python（习题6-9）

墨蓝 2023-03-13 03:28 125阅读 0赞

习题六：字符串和文本

通读程序，在每一行的上面写一行注解，给自己解释一下这一行的作用。

x = “There are %d type of people.” % 10 # 定义一个格式化字符串

 binary = "binary" # 定义一个字符串 
 do_not = "don't" # 定义一个字符串 
 # 定义一个格式化字符串 
 y = "Those who know %s and those who %s." % (binary, do_not) 
 print(x) # 输出定义的格式化字符串 
 print(y) # 输出定义的格式化字符串 
 print( "I said : %r." % x) # 把x作为参数传递给字符串打印 
 print( "I also said: '%s'." % y) # 把y作为参数传递给字符串打印 
 hilarious = False # 定义一个布尔型变量 
 joke_evaluation = "Isn't that joke so funny?! %r" # 定义一个字符串 
 # 打印字符串，将布尔型作为参数，传递给字符串的占位符 
 print(joke_evaluation % hilarious) 
 w = "This is the left side of..." # 定义一个字符串 
 e = "a string with a right side." # 定义一个字符串 
 print(w+e) # 打印合并两个字符串

找到所有的”字符串包含字符串”的位置，总共有四个位置。

y = “Those who know %s and those who %s.” % (binary, do_not)

print(“I said : %r.” % x)

print(“I also said: ‘%s’.” % y)

joke_evaluation = “Isn’t that joke so funny?! %r”
你确定只有四个位置吗？你怎么知道的？没准我在骗你呢。
解释一下为什么 w 和 e 用 + 连起来就可以生成一个更长的字符串。

因为w和e都是字符串，有博客说是调用了jion的方法。如果是两个数值的话，+最后就是加法运算的结果

习题七：更多打印

逆向阅读，在每一行的上面加一行注解。
倒着朗读出来，找出自己的错误。
从现在开始，把你的错误记录下来，写在一张纸上。
在开始下一节习题时，阅读一遍你记录下来的错误，并且尽量避免在下个练习中再犯同样的错误。

记住，每个人都会犯错误。程序员和魔术师一样，他们希望大家认为他们从不犯错，不过这只是表象而已，他们每时每刻都在犯错。

print( “Mary had a little lamd.”)

  print( "Its fleece was white as %s." % 'snow') 
  print( "And everywhere that Mary went.") 
  print( "." * 10) 
  end1 = "c" 
  end2 = "h" 
  end3 = "e" 
  end4 = "e" 
  end5 = "s" 
  end6 = "e" 
  end7 = "B" 
  end8 = "u" 
  end9 = "r" 
  end10 = "g" 
  end11 = "e" 
  end12 = "r" 
  print(end1+end2+end3+end4+end5+end6,end= " ") 
  print(end7+end8+end9+end10+end11+end12)

70 1

习题八：打印，打印

formatter = "%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.", 
     "Nut it didn't sing.", 
     "So I said goodnight" 
     ))

70 2

自己检查结果，记录你犯过的错误，并且在下个练习中尽量不犯同样的错误。
注意最后一行程序中既有单引号又有双引号，你觉得它是如何工作的？

查了一下单引号双引号的问题：字符串中既可以有单引号也可以有双引号，单引号可以括双引号，双引号可以括单引号；单不能扩单，双不能括双

之所以在输出的时候有单引号是因为引用字符%r，上面参考博文python中%r和%s的区别里对%s和%r的区别分析的很清楚。

%r打印可以重现它代表的对象。

习题九：打印、打印、打印

自己检查结果，记录你犯过的错误，并且在下个练习中尽量不犯同样的错误。

days = "Mon Tue Wed Thu Fri Sat Sun" 
     months = "Jan\nFed\nMar\nApr\nMay\nJun\nJul\nAug" 
     print( "Here are the days: ", days) 
     print( "Here are the months: ", months) 
     print( """ 
     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. 
     """)