《笨办法学python》加分习题25——我的答案

这是我自己学习的答案，会尽力写的比较好。还望大家能够提出我的不足和错误，谢谢！

文中例题：

def break_words(stuff):
"""This function will break up words for us."""
words = stuff.split(' ')
return words

def sort_words(words):
"""Sorts the words."""
return sorted(words)

def print_first_word(words):
"""Prints the first word after popping it off."""
word = words.pop(0)
print word

def print_last_word(words):
"""Prints the last word after popping it off."""
word = words.pop(-1)
print word

def sort_sentence(sentence):
"""Takes in a full sentence and returns the sorted words."""
words = break_words(sentence)
return sort_words(words)

def print_first_and_last(sentence):
"""Prints the first and last words of the sentence."""
words = break_words(sentence)
print_first_word(words)
print_last_word(words)

def print_first_and_last_sorted(sentence):
"""Sorts the words then prints the first and last one."""
words = sort_sentence(sentence)
print_first_word(words)
print_last_word(words)

文中运行使用的是shell，由于我想保存下运行代码，我就再编辑了一份可以运行ex25.py的ex25_run.py。功能和文中shell所使用的一致，只是在错误wrods那里，因为不能运行所以就没有那一行了。

ex25_run.py:

import ex25

sentence = "All good things come to those who wait."
words = ex25.break_words(sentence)
print words

sorted_words = ex25.sort_words(words)
print sorted_words

ex25.print_first_word(words)

ex25.print_last_word(words)

print words

ex25.print_first_word(sorted_words)

ex25.print_last_word(sorted_words)

print sorted_words

sorted_words = ex25.sort_sentence(sentence)
print sorted_words

ex25.print_first_and_last(sentence)

ex25.print_first_and_last_sorted(sentence)

运行结果：

/usr/bin/python2.7 /home/yxwang/Desktop/pystu/20170821/ex25_run.py
['All', 'good', 'things', 'come', 'to', 'those', 'who', 'wait.']
['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']
All
wait.
['good', 'things', 'come', 'to', 'those', 'who']
All
who
['come', 'good', 'things', 'those', 'to', 'wait.']
['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']
All
wait.
All
who

截图太长，不懂怎么截图，就复制当代码粘贴了。

习题答案：

1、我这里讲的行数针对我上文提到的ex25_run.py

16-18行和10-12行功能一致，打印并且去掉那个位置的列表元素

20行 打印剩下的列表元素

22行 sorted_words赋值为排序过的列表

23行 打印出来

25行是个复合函数，这个函数内行另外三个函数，作用和之前一样

27行如上。