hdf5数据库中的不可见数据(使用Python / Pandas / ViTables)

时间:2013-10-07 23:14:28

标签: python pandas hdf5

我有一个hdf5数据库,这给我带来了一些麻烦。

它应包含3,000个表,其中包含6列(整数和浮点数)以及索引(日期)和可变行数(从100到10,000,000)。

从昨天开始,当我使用ViTables查看数据库时,我会错过数千个表。我用它来在ViTables中看到它们。但数据仍然存在:我仍然可以通过Pandas访问它们。

数据分组如下:type/source/id

例如,我可以使用:

检索id1和id2
 with pd.get_store(HDF_DATABASE) as store:
     print store['type1/source1/id1']
     print store['type2/source2/id2']

但是从ViTables,我看不到type2/source2/id2

此外,> print store会列出type1/source1/id1,但不列出type2/source2/id2

关于如何修复这些“隐形”数据表的任何建议?

编辑:

  • Typos
  • Windows 7 32位/ Python 2.7.5 / Pandas 0.12.0(及其他 过去的版本)
  • ptdump file:http://pastebin.com/7mB6bT2T
  • 正如人们所料,我混淆了类型来源id
  • 看起来数据不再被引用,但只要数据库不是ptrepack-ed,它仍然存在。

EDIT2:

  • 我完全丢失了原始数据库:我再也无法访问它了。格式无法识别。
  • 用于插入新数据的此语句(以及类似的其他语句)返回NaturalNameWarning警告:store.append('equity/bloomberg/4615238QCN_Equity', df)。它不符合产生警告的自然命名要求。这可能与遇到的问题有关。

1 个答案:

答案 0 :(得分:0)

示例会话

In [1]: store = pd.HDFStore('test.h5')

In [2]: store['node()'] = Series(np.arange(10))
/usr/local/lib/python2.7/site-packages/tables/path.py:99: NaturalNameWarning: object name is not a valid Python identifier: 'node()'; it does not match the pattern ``^[a-zA-Z_][a-zA-Z0-9_]*$``; you will not be able to use natural naming to access this object; using ``getattr()`` will still work, though
  NaturalNameWarning)

In [3]: store
Out[3]: 
<class 'pandas.io.pytables.HDFStore'>
File path: test.h5
/df                frame_table  (typ->appendable,nrows->11,ncols->2,indexers->[index],dc->[A,B])
/node()            series       (shape->[10])                                                   

In [4]: store.keys()
Out[4]: ['/df', '/node()']

In [5]: store['node()/foo'] = Series(np.arange(10))

In [6]: store.keys()
Out[6]: ['/df', '/node()', '/node()/foo']

In [7]: store
Out[7]: 
<class 'pandas.io.pytables.HDFStore'>
File path: test.h5
/df                    frame_table  (typ->appendable,nrows->11,ncols->2,indexers->[index],dc->[A,B])
/node()                series       (shape->[10])                                                   
/node()/foo            series       (shape->[10])                                                   

In [8]: store['my_type\mysource\id_01_01'] = Series(np.arange(10))
/usr/local/lib/python2.7/site-packages/tables/path.py:99: NaturalNameWarning: object name is not a valid Python identifier: 'my_type\\mysource\\id_01_01'; it does not match the pattern ``^[a-zA-Z_][a-zA-Z0-9_]*$``; you will not be able to use natural naming to access this object; using ``getattr()`` will still work, though
  NaturalNameWarning)

In [9]: store
Out[9]: 
<class 'pandas.io.pytables.HDFStore'>
File path: test.h5
/df                                   frame_table  (typ->appendable,nrows->11,ncols->2,indexers->[index],dc->[A,B])
/my_type\mysource\id_01_01            series       (shape->[10])                                                   
/node()                               series       (shape->[10])                                                   
/node()/foo                           series       (shape->[10])                                                   

In [10]: store.keys()
Out[10]: ['/df', '/my_type\\mysource\\id_01_01', '/node()', '/node()/foo']

In [11]: store['my_type/mysource/id_01_01'] = Series(np.arange(10))

In [12]: store
Out[12]: 
<class 'pandas.io.pytables.HDFStore'>
File path: test.h5
/df                                   frame_table  (typ->appendable,nrows->11,ncols->2,indexers->[index],dc->[A,B])
/my_type\mysource\id_01_01            series       (shape->[10])                                                   
/node()                               series       (shape->[10])                                                   
/node()/foo                           series       (shape->[10])                                                   
/my_type/mysource/id_01_01            series       (shape->[10])                                                   

问题是标识符'my_type \ mysource \ id_01_01`没有按照你的想法行事,它看起来像文件路径。您需要反斜杠,而不是正斜杠(因为它们取决于架构)。理论上虽然这可行(但为了避免警告,你可能想要改变这些名称)。