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DOC: ref / val caveat, point at pandas methods #3399

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35 changes: 23 additions & 12 deletions doc/source/10min.rst
Original file line number Diff line number Diff line change
Expand Up @@ -121,8 +121,14 @@ Sorting by values
Selection
---------

See the :ref:`Indexing section <indexing>`
.. note::

While standard Python / Numpy expressions for selecting and setting are
intuitive and come handy for interactive work, for production code, we
recommend the optimized pandas data access methods, ``.at``, ``.iat``,
``.loc``, ``.iloc`` and ``.ix``.

See the :ref:`Indexing section <indexing>` and below.

Getting
~~~~~~~
Expand Down Expand Up @@ -230,7 +236,8 @@ For getting fast access to a scalar (equiv to the prior method)
df.iat[1,1]

There is one signficant departure from standard python/numpy slicing semantics.
python/numpy allow slicing past the end of an array without an associated error.
python/numpy allow slicing past the end of an array without an associated
error.

.. ipython:: python

Expand All @@ -239,7 +246,8 @@ python/numpy allow slicing past the end of an array without an associated error.
x[4:10]
x[8:10]

Pandas will detect this and raise ``IndexError``, rather than return an empty structure.
Pandas will detect this and raise ``IndexError``, rather than return an empty
structure.

::

Expand Down Expand Up @@ -306,11 +314,13 @@ A ``where`` operation with setting.
df2[df2 > 0] = -df2
df2


Missing Data
------------

Pandas primarily uses the value ``np.nan`` to represent missing data. It
is by default not included in computations. See the :ref:`Missing Data section <missing_data>`
Pandas primarily uses the value ``np.nan`` to represent missing data. It is by
default not included in computations. See the :ref:`Missing Data section
<missing_data>`

Reindexing allows you to change/add/delete the index on a specified axis. This
returns a copy of the data.
Expand Down Expand Up @@ -457,8 +467,8 @@ Append rows to a dataframe. See the :ref:`Appending <merging.concatenation>`
Grouping
--------

By "group by" we are referring to a process involving one or more of the following
steps
By "group by" we are referring to a process involving one or more of the
following steps

- **Splitting** the data into groups based on some criteria
- **Applying** a function to each group independently
Expand All @@ -481,7 +491,8 @@ Grouping and then applying a function ``sum`` to the resulting groups.

df.groupby('A').sum()

Grouping by multiple columns forms a hierarchical index, which we then apply the function.
Grouping by multiple columns forms a hierarchical index, which we then apply
the function.

.. ipython:: python

Expand Down Expand Up @@ -547,10 +558,10 @@ We can produce pivot tables from this data very easily:
Time Series
-----------

Pandas has simple, powerful, and efficient functionality for
performing resampling operations during frequency conversion (e.g., converting
secondly data into 5-minutely data). This is extremely common in, but not
limited to, financial applications. See the :ref:`Time Series section <timeseries>`
Pandas has simple, powerful, and efficient functionality for performing
resampling operations during frequency conversion (e.g., converting secondly
data into 5-minutely data). This is extremely common in, but not limited to,
financial applications. See the :ref:`Time Series section <timeseries>`

.. ipython:: python

Expand Down
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