笨办法学python第7课

print("its fleece was white as {}.".format('snow'))  #格式str.format()
print("and everywhere that mary went.")   #打印字符串
print("."*10)  #what'd that do?  #字符串*10,用其他的符号都不行，只能用乘法

end1 = "c"  #字符串赋值
end2 = "h"
end3 = "e"
end4 = "e"
end5 = "s"
end6 = "e"
end7 = "B"
end8 = "u"
end9 = "r"
end10 = "g"
end11 = "e"
end12 = "r"

#watch  end = ' ' at the end t

print(end1 + end2 + end3 + end4 + end5 +end6, end =' ')  #end=' '应该是占位符，留给后面的那个单词
print(end7 + end8 + end9 + end10 + end11 +end12)

运行结果：
$ python3.6 ex7.py
Mary had a little lamb.
Its fleece was white as snow.
And everywhere that Mary went.
..........
Cheese Burger

Study Drills练习题
For these next few exercises, you will have the exact same Study Drills.
1. Go back through and write a comment on what each line does.
done
2. Read each one backward or out loud to find your errors.

done

3. From now on, when you make mistakes, write down on a piece of paper what kind of mistake you made.

从现在开始，记录每一个错误

4. When you go to the next exercise, look at the mistakes you have made and try not to make
them in this new one.

ok

5. Remember that everyone makes mistakes. Programmers are like magicians who fool everyone
into thinking they are perfect and never wrong, but it’s all an act. They make mistakes all the  time

ok


Common Student Questions常见问题：
1.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.

2.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.

3.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