目的:写程序,逐行研究,弄懂它。
定义函数
# coding=utf-8
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 poping it off."""
word = words.pop(0)
print(word)
def print_last_word(words):
"""Prints the last word after poping if 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)
调用函数
在Windows命令窗口,执行脚本,看下脚本是否报错,如果报错,请仔细检查代码再执行。
把脚本放到F:\python\Lib下,在Python交互页面,进行函数调用
具体调用步骤如下:
Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 18:41:36) [MSC v.1900 64 bit (AMD64)] on win32
Type "copyright", "credits" or "license()" for more information.
>>> import new21
>>> sentence = "All good things come to those who wait."
>>> words = new21.break_words(sentence)
>>> words
['All', 'good', 'things', 'come', 'to', 'those', 'who', 'wait.']
>>> sorted_words = new21.sort_words(words)
>>> sorted_words
['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']
>>> new21.print_first_word(words)
All
>>> new21.print_last_word(words)
wait.
>>> words
['good', 'things', 'come', 'to', 'those', 'who']
>>> new21.print_first_word(sorted_words)
All
>>> new21.print_last_word(sorted_words)
who
>>> sorted_words
['come', 'good', 'things', 'those', 'to', 'wait.']
>>> sorted_words = new21.sort_sentence(sentence)
>>> sorted_words
['All', 'come', 'good', 'things', 'those', 'to', 'wait.', 'who']
>>> new21.print_first_and_last(sentence)
All
wait.
>>> new21.print_first_and_last_sorted(sentence)
All
who
>>>
多次练习,要清楚定义函数和调用函数的方法,怎么来的?怎么用的?
在定义函数的过程中,整理了一些问题:
参数:str -- 分隔符,默认为所有的空字符,包括空格、换行(\n)、制表符(\t)等。num -- 分割次数。
返回值:返回分割后的字符串列表。