Skip to content

DOC: Column indexes should use the same metadata as columns #17795

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 3 commits into from
Oct 5, 2017
Merged

DOC: Column indexes should use the same metadata as columns #17795

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
d3a1639
DOC: Column indexes should use the same metadata as columns
cpcloud Oct 5, 2017
418f173
Fix metadata field name
cpcloud Oct 5, 2017
b0d34cf
Remove column_index_names
cpcloud Oct 5, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
19 changes: 11 additions & 8 deletions doc/source/developer.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,20 +45,19 @@ So that a ``pandas.DataFrame`` can be faithfully reconstructed, we store a
.. code-block:: text

{'index_columns': ['__index_level_0__', '__index_level_1__', ...],
'column_index_names': [<column index level name 0>, <column index level name 1>, ...],
'column_index_dtypes': [<dtype 0>, <dtype 1>, ..., <dtype N>]
'column_indexes': [<ci0>, <ci1>, ..., <ciN>],
'columns': [<c0>, <c1>, ...],
'pandas_version': $VERSION}

Here, ``<c0>`` and so forth are dictionaries containing the metadata for each
column. This has JSON form:
Here, ``<c0>``/``<ci0>`` and so forth are dictionaries containing the metadata
for each column. This has JSON form:

.. code-block:: text

{'name': column_name,
'pandas_type': pandas_type,
'numpy_type': numpy_type,
'metadata': type_metadata}
'metadata': metadata}

``pandas_type`` is the logical type of the column, and is one of:

Expand All @@ -75,7 +74,7 @@ result of ``str(dtype)`` for the underlying NumPy array that holds the data. So
for ``datetimetz`` this is ``datetime64[ns]`` and for categorical, it may be
any of the supported integer categorical types.

The ``type_metadata`` is ``None`` except for:
The ``metadata`` field is ``None`` except for:

* ``datetimetz``: ``{'timezone': zone, 'unit': 'ns'}``, e.g. ``{'timezone',
'America/New_York', 'unit': 'ns'}``. The ``'unit'`` is optional, and if
Expand Down Expand Up @@ -108,8 +107,12 @@ As an example of fully-formed metadata:
.. code-block:: text

{'index_columns': ['__index_level_0__'],
'column_index_names': [None],
'column_index_dtypes': ['object'],
'column_indexes': [
{'name': None,
'pandas_type': 'string',
'numpy_type': 'object',
'metadata': None}
],
'columns': [
{'name': 'c0',
'pandas_type': 'int8',
Expand Down