python - 在 Python 中将文本与嵌套的 OrderedDict 分开

Question

这是我的 OrderedDict 对象，

a=OrderedDict([(u'p', [u'"The Exam Room" is a new series in which everyday medical questions are answered by physicians and professors from the Yale School of Medicine.', u'In our second episode: Dr. Stephen Strittmatter, Vincent Coates Professor of Neurology and director of the Adler Memory Clinic in Neurology, explains when memory loss can become a problem and what you can do to boost your brain power.', OrderedDict([(u'em', u'Produced & Hosted by Noah Golden')])])])

我想做的是从这个对象中获取文本，

>>> a.get('p')

并得到输出，

[u'"The Exam Room" is a new series in which everyday medical questions are answered by physicians and professors from the Yale School of Medicine.', u'In our second episode: Dr. Stephen Strittmatter, Vincent Coates Professor of Neurology and director of the Adler Memory Clinic in Neurology, explains when memory loss can become a problem and what you can do to boost your brain power.', OrderedDict([(u'em', u'Produced & Hosted by Noah Golden')])]

但生成的文本还包含一个 OrderedDict。

我如何合并来自 OrderedDict ,

的文本

预期输出:

The Exam Room" is a new series in which everyday medical questions are answered by physicians and professors from the Yale School of Medicine.', u'In our second episode: Dr. Stephen Strittmatter, Vincent Coates Professor of Neurology and director of the Adler Memory Clinic in Neurology, explains when memory loss can become a problem and what you can do to boost your brain power. Produced & Hosted by Noah Golden

Answer 1

如果您事先不知道类型的嵌套，这里的关键是递归。这是一个示例(为了便于阅读而对文本进行了格式化):

#!/usr/bin/env python

import collections

a = collections.OrderedDict([(u'p', [u""" 
    "The Exam Room" is a new series in
    which everyday medical questions are answered by physicians and 
    professors from the Yale School of Medicine.""", 
    u"""In our second episode: Dr. Stephen Strittmatter,
    Vincent Coates Professor of Neurology and director of
    the Adler Memory Clinic in Neurology, explains when 
    memory loss can become a problem and what you can do to 
    boost your brain power.""", 
    collections.OrderedDict([(u'em',
        u'Produced & Hosted by Noah Golden')])])])

现在展平对象，它可能是映射或列表。实现了三个选项:如果找到的值是一个字符串，我们只需将它附加到我们的 collector。如果它是一个 list 或一个 Mapping，我们再次调用 flatten。请注意，您可以使用 allowed kwarg 指定一些允许的标签:

def flatten(obj, allowed=(u'p', u'em')):
    collector = []

    def process(v, collector=collector):
        if isinstance(v, (list, collections.Mapping)):
            collector += flatten(v, allowed=allowed)
        elif isinstance(v, basestring):
            collector.append(v)
        else:
            raise ValueError('Cannot handle type: {t}'.format(t=v.__class__))

    if isinstance(obj, list):
        for v in obj:
            process(v)

    if isinstance(obj, collections.Mapping):
        for k, v in obj.iteritems():
            if k in allowed:
                process(v)

    return collector

if __name__ == '__main__':
    print(flatten(a))

您的示例的结果将是一个三元素列表，看起来像这样:

[u'"The Exam Room" is a new series ...',
 u'In our second episode: ...',
 u'Produced & Hosted by Noah Golden']

现在，如果您想要单个字符串，只需加入现在扁平化的列表即可:

print(''.join(flatten(a)))