习题 7: 更多打印
现在我们将做一批练习，在练习的过程中你需要键入代码，并且让它们运行起来。我不会 解释太多，因为这节的内容都是以前熟悉过的。这节练习的目的是巩固你学到的东西。我们 几个练习后再见。不要跳过这些习题。不要复制粘贴！
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?
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. try removing it to see what happens
print end1 + end2 + end3 + end4 + end5 + end6,
print end7 + end8 + end9 + end10 + end11 + end12
What You Should See
$ python ex7.py
Mary had a little lamb.
Its fleece was white as snow.
And everywhere that Mary went.
..........
Cheese Burger
Study Drills
接下来几节的加分习题是一样的。
- 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。
Common Student Questions
| Why are you using the variable named 'snow'? |
|---|
| That's actually not a variable: it is just a string with the word snow in it. A variable wouldn't have the single-quotes around it. |
| Is it normal to write an English comment for every line of code like you say to do in Study Drill 1? |
| No, you write comments only to explain difficult to understand code or why you did something. Why is usually much more important, and then you try to write the code so that it explains how something is being done on its own. However, sometimes you have to write such nasty code to solve a problem that it does need a comment on every line. In this case it's strictly for you to practice translating code to English. |
| Can I use single-quotes or double-quotes to make a string or do they do different things? |
| In Python either way to make a string is acceptable although typically you'll use single-quotes for any short strings like 'a' or 'snow'. |
| Couldn't you just not use the comma , and turn the last two lines into one single-line print? |
| Yes, you could very easily, but then it'd be longer than 80 characters, which in Python is bad style. |
Copyright (C) 2010 by
Author: Zed Shaw
Translator：Zander Wong