python 笔记 继续进行输出练习，并进行格式化定义打印 ——12.23

习题7:更多打印

 

目的:巩固之前所学

 

 

ex7.py

# -*- coding: utf-8-*-

print "Mary had a little lamb."

print "Its fleece was white as %s."%'snow'

print "And everywhere that Mary went."

print "."*10 # what'd that do? I think it's 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"

 

# watch that comma at the end. tryremoving it to see what happens

print end1 + end2+ end3 + end4 +end5 +end6,

print end7 + end8+ end9 + end10 + end11 + end12

 

运行结果:

 

 

感悟与自我测试:

 

ex7_1.py

# -*- coding: utf-8-*-  #个人偏好中文，所以每次打这个定义编码用于熟悉

a ="."

b ="!!!!"

 

print a  * 10

print "(b + a) "* 5

print "$$$" * 4

 

运行结果:

 

 

 

 

习题8：打印 打印

 

ex8.py

# -*- coding: utf-8-*-

#对于%r 和%s ，一般字符串使用%s，%r大多用于测试debug，目前我还是不是非常理解。

formatter = "%r %r %r%r"

 

printformatter %(1,2, 3, 4)  # formatter 的中文翻译为“格式化”

print formatter %("one","two","there","four")

print formatter %(True,False,False,True)

print formatter %(formatter, formatter, formatter, formatter)

print formatter %(

     "I had thisthing.",

     "That you couldtype up right.",

     "But it didn'tsing.",

     "So I saidgoodnight."

)

 

 

运行结果:

 

感悟与自我测试:

变量也可以被定义成一种格式化输出，下面我们使用%f来测试下。

 

ex8_1.py

# -*- coding: utf-8-*-

formatter1 = "%4.3f"

formatter2 = "%d"

 

print formatter1 %(10.8888)

print formatter2 %(10.8888)

 

运行结果:

 

 

此处看起来一切正常，然而之后发现出错的情况。

ex8_2.py

 

# -*- coding: utf-8-*-

formatter1 = "%4.3f"

formatter2 = "%d"

 

print formatter1 %(10.8888,9.3333)

print formatter2 %(10.8888,2.222222)

 

 

运行结果:

 

 

ex8_3py

# -*- coding: utf-8-*-

formatter = "%r %r %r%r"

formatter1 = "%2.2f %2.3f%3.1f"

formatter2 = "%d"

number1 = 20.88888

number2 = 3.1312313

 

print formatter1 %(10.8888,3.3333,0.8888)

print formatter2 %(10.8888)

 

#换种思路，将数值赋予给变量，之后于打印中定义格式化输出

 

print "I have %4.3f dogs."%number1

print "She's got %s chocolates and %4.3f apples."%(number1, number2)

 

运行结果:

 

 

 

故总结出，括号中的每一个字符串都需要提前指定，并不是想当然的后面参照第一个标准