1

我一直在学习'Learn Python the Hard Way'，这段特殊的代码让我很头疼：

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

def sort_words(words):
    """Sort 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 = brea_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)

导入模块后，我会收到错误：

>>> import ex25
>>> sentence = "All good things come to those who wait."
>>> words = ex25.break_words(sentence)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "ex25.py", line 4, in break_words
    return words
NameError: global name 'words' is not defined

我哪里做错了？我检查了数百万次代码...

4

3 回答 3

5

你试过跑步吗

reload(ex25)

? 如果您导入一个文件，然后更改该文件，python 进程不知道您更改了它。您必须重新启动，或者告诉它再次查看模块。

于 2012-05-09T20:51:24.033 回答
1

正如我在评论中所说，我认为正在导入您的 pyc 文件而不是您的 py 代码。

于 2012-05-09T20:45:36.310 回答
0

假设上面的答案就足够了——你需要重新加载模块。在 NFS 文件系统上，我看到更改后没有重新编译 python 代码的问题（并且使用了旧的 pyc 文件）。如果“重新加载”不起作用，您可以尝试删除 pyc 文件并重新启动 python。

  ddzialak@pld ~$ python
  Python 2.7.2 (default, Aug 16 2011, 10:09:58)
  [GCC 4.6.1 20110714 (release)] on linux2
  Type "help", "copyright", "credits" or "license" for more information.
  >>> import ex25
  >>> sentence = "All good things come to those who wait."
  >>> words = ex25.break_words(sentence)
  >>> print words
  ['All', 'good', 'things', 'come', 'to', 'those', 'who', 'wait.']
于 2012-05-09T20:59:45.633 回答