源码

#命名函数
def break_words(stuff):
    """This function will break up words for us."""
    #设置变量words  使用.split()命令分割字符串
    words = stuff.split(' ')
    #返回
    return words
 
def sort_words(words):
    """Sorts the words."""
    #返回 使用sorted()命令升序排序
    return sorted(words)
 
def print_first_word(words):
    """Prints the first word after popping it off."""
    #.pop(0)命令删除并返回第一个元素
    word = words.pop(0)
    print(word)
 
def print_last_word(words):
    """Prints the last word after poping it off."""
    #.pop(-1)命令删除并返回最后一个元素
    word = words.pop(-1)
    print(word)
 
def sort_sentence(sentence):  #sentence句子
    """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)

使用python 自带shell回显

Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 22:22:05) [MSC v.1916 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license()" for more information.
 
>>> import sys
>>> sys.path.append(r"C:\Users\gw\test")
>>> sys.path
['', 'C:\\Python37\\Lib\\idlelib', 'C:\\Python37\\python37.zip', 'C:\\Python37\\DLLs', 'C:\\Python37\\lib', 'C:\\Python37', 'C:\\Python37\\lib\\site-packages', 'C:\\Users\\gw\\test']
>>> import ex25
>>> sentence = "All good things come to those who wait."
>>> words = ex25.break_words(sentence)
>>> words
['All', 'good', 'things', 'come', 'to', 'those', 'who', 'wait.']
>>> sorted_words = ex25.sort_words(words)
>>> sorted_words
['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']
>>> ex25.print_first_word(words)
All
>>> ex25.print_last_word(words)
wait.
>>> words
['good', 'things', 'come', 'to', 'those', 'who']
>>> ex25.print_first_word(sorted_words)
All
>>> ex25.print_last_word(sorted_words)
who
>>> sorted_words
['come', 'good', 'things', 'those', 'to', 'wait.']
>>> sorted_words = ex25.sort_sentence(sentence)
>>> sorted_words
['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']
>>> ex25.print_first_and_last(sentence)
All
wait.
>>> ex25.print_first_and_last_sorted(sentence)
All
who
>>>