Exercise 24:更多的练习

原文链接：http://learnpythonthehardway.org/book/ex24.html

       这一部分很快就要告一段落了。你在转向开始学习如何编写正真有用的程序之前你应该在你“指下”积累了足够的Python代码，所有你应该做更多的练习。这次的练习比较长你需要足够的耐心去学习它。下一次的练习将和这次的类似。做完它们，做到完全正确，仔细做好检查。

print "Let's practice everything."
print 'You\'d need to know \'bout escapes with \\ that do \n newlies and \t tabs.'

poem = """
\tThe lovely world
with logic so firmly planted
cannot discern \r the needs of love
nor comprehend passion from intuition
and requires an explanation
\n\t\twhere there is none.
"""

print "----------------"
print poem
print "----------------"

five  = 10 - 2 + 3 - 6
print "This should be five: %s" % five

def secret_formula(started):
	jelly_beans = started * 500
	jars = jelly_beans / 1000
	crates = jars / 100
	return jelly_beans ,jars ,crates

start_point = 10000
beans ,jars ,crates = secret_formula(start_point)

print "With a starting point of: %d" % start_point
print "We'd have %d beans ,%d jars ,and %d crates." % (beans ,jars ,crates)

start_point = start_point / 10

print "We can also do that this way:"
print "We'd have %d beans ,%d jars ,and %d crates." % secret_formula(start_point)

输出结果如下：

c:\>python ex24.py
Let's practice everything.
You'd need to know 'bout escapes with \ that do
 newlies and     tabs.
----------------

        The lovely world
with logic so firmly planted
 the needs of love
nor comprehend passion from intuition
and requires an explanation

                where there is none.

----------------
This should be five: 5
With a starting point of: 10000
We'd have 5000000 beans ,5000 jars ,and 50 crates.
We can also do that this way:
We'd have 500000 beans ,500 jars ,and 5 crates.

1、做好代码检查：从后往前阅览对照，将代码大声的读出来，在迷惑的地方做好注释。

2、故意把代码改错，然后运行看看你得到了什么样的错误。确保你可以自己解决这个错误。

学生遇见的常见问题：