我正在学习如何使用python在网站'学习python艰难的方式'exercise 25的练习之后进行编码。
问题在于我无法完成练习25因为我有一个我无法弄清楚的问题。
我正在输入python控制台但是在指令编号8 ex25.print_last_word(words)我有这个错误：
>>> ex25.print_last_word(words)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "ex25.py", line 19, in print_last_word
word = words.pop(-1)
NameError: global name 'POP' is not defined
这是我的代码。
def break_words(stuff):
"""This function will break up word for us, praticamente
divide in blank space tra le parole"""
words = stuff.split(' ')
return words
def sort_words(words):
'''sort the words, ordina la parola??'''
return sorted(words)
def print_first_word(words):
'''print the first word after popping it off, ossia trova pop(0) trova
la lettera iniziale della parola..'''
word = words.pop(0)
print word
def print_last_word(words):
'''print the last word after popping it off'''
word = words.pop(-1)
print word
def sort_sentence(sentence):
'''takes in a full sentence and return the sorted words.'''
words = break_words(sentence)
words = break_words(words)
def print_first_and_last(sentence):
'''prints the first and the 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'''
word = sort_sentence(sentence)
print_first_word(words)
print_last_word(words)
答案 0 :(得分：0)
Python解释器引发的错误与您发布的代码不符，因为代码中从未提及POP。
该错误可能表示解释器在内存中对模块ex25的定义与文本文件ex25.py中的定义不同。您可以refresh the definition使用
>>> reload(ex25)
请注意，每次修改ex25.py时都必须执行此操作。
出于这个原因，您可能会发现修改ex25.py更容易，因此可以通过添加
if __name__ == '__main__':
words = ...
print_last_word(words)
到ex25.py的末尾，并从命令行运行脚本：
python ex25.py