如何在 pandas HDStore(pyTables)中访问索引 [英] how to access index in a pandas HDStore (pyTables)

问题描述

我有一个带有多索引的大型HDFStore.如何获得其中一个指数水平?我看到我可以像这样访问colindex:

I have a large HDFStore with a multi-index. How can I get a hold of one of the index levels? I see I can access the colindex like so:

 store._handle.root.data.table.colindexes

但尚未获得列索引之一的列表.

But have yet to get a list of one of the column indexes.

推荐答案

以表格格式存储(请注意，在0.13中，您将传递format='table')

Store in table format (note that in 0.13 you will pass format='table')

In [24]: df_mi.to_hdf('test.h5','df_mi',table=True,mode='w')

检索单个列. MI被存储为列！

To retrieve a single column. The MI are stored as columns!

In [25]: store = pd.HDFStore('test.h5')

In [26]: store.select_column('df_mi','foo')
Out[26]: 
0    foo
1    foo
2    foo
3    bar
4    bar
5    baz
6    baz
7    qux
8    qux
9    qux
dtype: object

In [30]: store.select_column('df_mi','bar')
Out[30]: 
0      one
1      two
2    three
3      one
4      two
5      two
6    three
7      one
8      two
9    three
dtype: object

In [31]: store.close()

这篇关于如何在 pandas HDStore(pyTables)中访问索引的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！