==============
Django Pandas
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Tools for working with pandas <http://pandas.pydata.org>
_ in your Django
projects
Contributors
Christopher Clarke <https://github.com/chrisdev>
_Bertrand Bordage <https://github.com/BertrandBordage>
_Guillaume Thomas <https://github.com/gtnx>
_Parbhat Puri <https://parbhatpuri.com/>
_Fredrik Burman (coachHIPPO) <https://www.coachhippo.com>
_Safe Hammad <http://safehammad.com>
_Jeff Sternber <https://www.linkedin.com/in/jeffsternberg>
_@MiddleFork <https://github.com/MiddleFork>
_Daniel Andrlik <https://github.com/andrlik>
_Kevin Abbot <https://github.com/kgabbott>
_Yousuf Jawwad <https://github.com/ysfjwd>
_@henhuy <https://github.com/henhuy>
_Hélio Meira Lins <https://github.com/meiralins>
_@utpyngo <https://github.com/utpyngo>
_Anthony Monthe <https://github.com/ZuluPro>
_Vincent Toupet <https://github.com/vtoupet>
_Anton Ian Sipos <https://github.com/aisipos>
_Thomas Grainger <https://github.com/graingert/>
_Ryan Smith <https://github.com/bixbyr/>
_
What's New
This is release facilitates running of test with Python 3.10 and automates
the publishing of the package to PYPI as per PR #146
_
(again much thanks @graingert). As usual we have attempted support legacy
versions of Python/Django/Pandas and this sometimes results in deperation errors
being displayed in when test are run. To avoid use python -Werror runtests.py
.. _#146
: https://github.com/chrisdev/django-pandas/pull/146
Dependencies
django-pandas
supports Django
_ (>=1.4.5) or later
and requires django-model-utils
_ (>= 1.4.0) and Pandas
_ (>= 0.12.0).
Note because of problems with the requires
directive of setuptools
you probably need to install numpy
in your virtualenv before you install
this package or if you want to run the test suite ::
pip install numpy
pip install -e .[test]
python runtests.py
Some pandas
functionality requires parts of the Scipy stack.
You may wish to consult http://www.scipy.org/install.html
for more information on installing the Scipy
stack.
You need to install your preferred version of Django.
as that Django 2 does not support Python 2.
.. _Django: http://djangoproject.com/
.. _django-model-utils: http://pypi.python.org/pypi/django-model-utils
.. _Pandas: http://pandas.pydata.org
Contributing
Please file bugs and send pull requests to the GitHub repository
_ and issue tracker
_.
.. _GitHub repository: https://github.com/chrisdev/django-pandas/
.. _issue tracker: https://github.com/chrisdev/django-pandas/issues
Installation
Start by creating a new virtualenv
for your project ::
mkvirtualenv myproject
Next install numpy
and pandas
and optionally scipy
::
pip install numpy
pip install pandas
You may want to consult the scipy documentation
_ for more information
on installing the Scipy
stack.
.. _scipy documentation: http://www.scipy.org/install.html
Finally, install django-pandas
using pip
::
pip install django-pandas
or install the development version from github
::
pip install https://github.com/chrisdev/django-pandas/tarball/master
Usage
IO Module
The django-pandas.io
module provides some convenience methods to
facilitate the creation of DataFrames from Django QuerySets.
read_frame
^^^^^^^^^^^
Parameters
- qs: A Django QuerySet.
- fieldnames: A list of model field names to use in creating the ``DataFrame``.
You can span a relationship in the usual Django way
by using double underscores to specify a related field
in another model
- index_col: Use specify the field name to use for the ``DataFrame`` index.
If the index
field is not in the field list it will be appended
- coerce_float : Boolean, defaults to True
Attempt to convert values to non-string,
non-numeric objects (like decimal.Decimal)
to floating point.
- verbose: If this is ``True`` then populate the DataFrame with the
human readable versions of any foreign key or choice fields
else use the actual values set in the model.
- column_names: If not None, use to override the column names in the
DateFrame
Examples
^^^^^^^^^
Assume that this is your model::
class MyModel(models.Model):
full_name = models.CharField(max_length=25)
age = models.IntegerField()
department = models.CharField(max_length=3)
wage = models.FloatField()
First create a query set::
from django_pandas.io import read_frame
qs = MyModel.objects.all()
To create a dataframe using all the fields in the underlying model ::
df = read_frame(qs)
The df
will contain human readable column values for foreign key and choice
fields. The DataFrame
will include all the fields in the underlying
model including the primary key.
To create a DataFrame using specified field names::
df = read_frame(qs, fieldnames=['age', 'wage', 'full_name'])
To set full_name
as the DataFrame
index ::
qs.to_dataframe(['age', 'wage'], index_col='full_name'])
You can use filters and excludes ::
qs.filter(age__gt=20, department='IT').to_dataframe(index_col='full_name')
DataFrameManager
django-pandas
provides a custom manager to use with models that
you want to render as Pandas Dataframes. The DataFrameManager
manager provides the to_dataframe
method that returns
your models queryset as a Pandas DataFrame. To use the DataFrameManager, first
override the default manager (objects
) in your model's definition
as shown in the example below ::
#models.py
from django_pandas.managers import DataFrameManager
class MyModel(models.Model):
full_name = models.CharField(max_length=25)
age = models.IntegerField()
department = models.CharField(max_length=3)
wage = models.FloatField()
objects = DataFrameManager()
This will give you access to the following QuerySet methods:
- ``to_dataframe``
- ``to_timeseries``
- ``to_pivot_table``
to_dataframe
^^^^^^^^^^^^^
Returns a DataFrame from the QuerySet
Parameters
- fieldnames: The model field names to utilise in creating the frame.
to span a relationship, use the field name of related
fields across models, separated by double underscores,
- index: specify the field to use for the index. If the index
field is not in the field list it will be appended
- coerce_float: Attempt to convert the numeric non-string data
like object, decimal etc. to float if possible
- verbose: If this is ``True`` then populate the DataFrame with the
human readable versions of any foreign key or choice fields
else use the actual value set in the model.
Examples
^^^^^^^^^
Create a dataframe using all the fields in your model as follows ::
qs = MyModel.objects.all()
df = qs.to_dataframe()
This will include your primary key. To create a DataFrame using specified
field names::
df = qs.to_dataframe(fieldnames=['age', 'department', 'wage'])
To set full_name
as the index ::
qs.to_dataframe(['age', 'department', 'wage'], index='full_name'])
You can use filters and excludes ::
qs.filter(age__gt=20, department='IT').to_dataframe(index='full_name')
to_timeseries
A convenience method for creating a time series i.e the
DataFrame index is instance of a DateTime or PeriodIndex
Parameters
- fieldnames: The model field names to utilise in creating the frame.
to span a relationship, just use the field name of related
fields across models, separated by double underscores,
- index: specify the field to use for the index. If the index
field is not in the field list it will be appended. This
is mandatory.
- storage: Specify if the queryset uses the `wide` or `long` format
for data.
- pivot_columns: Required once the you specify `long` format
storage. This could either be a list or string identifying
the field name or combination of field. If the pivot_column
is a single column then the unique values in this column become
a new columns in the DataFrame
If the pivot column is a list the values in these columns are
concatenated (using the '-' as a separator)
and these values are used for the new timeseries columns
- values: Also required if you utilize the `long` storage the
values column name is use for populating new frame values
- freq: the offset string or object representing a target conversion
- rs_kwargs: Arguments based on pandas.DataFrame.resample
- verbose: If this is ``True`` then populate the DataFrame with the
human readable versions of any foreign key or choice fields
else use the actual value set in the model.
Examples
^^^^^^^^^
Using a long storage format ::
#models.py
class LongTimeSeries(models.Model):
date_ix = models.DateTimeField()
series_name = models.CharField(max_length=100)
value = models.FloatField()
objects = DataFrameManager()
Some sample data:::
======== ===== =====
date_ix series_name value
======== ===== ======
2010-01-01 gdp 204699
2010-01-01 inflation 2.0
2010-01-01 wages 100.7
2010-02-01 gdp 204704
2010-02-01 inflation 2.4
2010-03-01 wages 100.4
2010-02-01 gdp 205966
2010-02-01 inflation 2.5
2010-03-01 wages 100.5
========== ========== ======
Create a QuerySet ::
qs = LongTimeSeries.objects.filter(date_ix__year__gte=2010)
Create a timeseries dataframe ::
df = qs.to_timeseries(index='date_ix',
pivot_columns='series_name',
values='value',
storage='long')
df.head()
date_ix gdp inflation wages
2010-01-01 204966 2.0 100.7
2010-02-01 204704 2.4 100.4
2010-03-01 205966 2.5 100.5
Using a wide storage format ::
class WideTimeSeries(models.Model):
date_ix = models.DateTimeField()
col1 = models.FloatField()
col2 = models.FloatField()
col3 = models.FloatField()
col4 = models.FloatField()
objects = DataFrameManager()
qs = WideTimeSeries.objects.all()
rs_kwargs = {'how': 'sum', 'kind': 'period'}
df = qs.to_timeseries(index='date_ix', pivot_columns='series_name',
values='value', storage='long',
freq='M', rs_kwargs=rs_kwargs)
to_pivot_table
A convenience method for creating a pivot table from a QuerySet
Parameters
- fieldnames: The model field names to utilise in creating the frame.
to span a relationship, just use the field name of related
fields across models, separated by double underscores,
- values : column to aggregate, optional
- rows : list of column names or arrays to group on
Keys to group on the x-axis of the pivot table
- cols : list of column names or arrays to group on
Keys to group on the y-axis of the pivot table
- aggfunc : function, default numpy.mean, or list of functions
If list of functions passed, the resulting pivot table will have
hierarchical columns whose top level are the function names
(inferred from the function objects themselves)
- fill_value : scalar, default None
Value to replace missing values with
- margins : boolean, default False
Add all row / columns (e.g. for subtotal / grand totals)
- dropna : boolean, default True
Example
::
# models.py
class PivotData(models.Model):
row_col_a = models.CharField(max_length=15)
row_col_b = models.CharField(max_length=15)
row_col_c = models.CharField(max_length=15)
value_col_d = models.FloatField()
value_col_e = models.FloatField()
value_col_f = models.FloatField()
objects = DataFrameManager()
Usage ::
rows = ['row_col_a', 'row_col_b']
cols = ['row_col_c']
pt = qs.to_pivot_table(values='value_col_d', rows=rows, cols=cols)
.. end-here
CHANGES
0.6.7 (2024-03-27)
Fix several deprecation warnings in pandas 2.1 which became actual errors in 2.2
as per #158
_ (thanks to @bixbyr)
.. _#158
: https://github.com/chrisdev/django-pandas/pull/158
0.6.6 (2021-10-27)
The main feature of this is release in the use of a GHA to
automate the publishing of the package to PYPI as per PR #146
_
(again much thanks @graingert). Several other minor issues have also
been addressed.
.. _#146
: https://github.com/chrisdev/django-pandas/pull/146
0.6.5 (2021-10-15)
This version added support for Pandas >=1.3 (thanks to @graingert)
Other Changes:
-
Migrated from Travis to Github Actions for CI (also @graingert)
-
Avoid the use of deprecated methods #139
_ and #142
_ (again much thanks @graingert)
-
Fix for issue #135
_ (Thanks @Yonimdo)
-
Silence Django 3.2 errors on testing on etc. #133
_ thanks @whyscream.
.. _#139
: https://github.com/chrisdev/django-pandas/issues/135
.. _#142
: https://github.com/chrisdev/django-pandas/issues/142
.. _#135
: https://github.com/chrisdev/django-pandas/issues/135
.. _#133
: https://github.com/chrisdev/django-pandas/issues/133
0.6.4 (2021-02-08)
Bumped version number as the previous release was incorrectly uploaded
to pypi
0.6.1 (2020-05-26)
Supports the latest release of Pandas 1.0.3
0.6.0 (2019-01-11)
Removes compatibility with Django versions < 1.8
0.5.2 (2019-01-3)
This is the last version that supports Django < 1.8
- Improved coerce_float option (thanks @ZuluPro )
- Ensure compatibility with legacy versions of Django ( < 1.8)
- Test pass with Django 2+ and python 3.7
0.5.1 (2018-01-26)
- Address Unicode decode error when installing with pip3 on docker (Thanks @utapyngo)
0.5.0 (2018-01-20)
- Django 2.0 compatibility (Thanks @meirains)
0.4.5 (2017-10-4)
- A Fix for fieldname deduplication bug thanks to @kgabbott
0.4.4 (2017-07-16)
- The
verbose
argument now handles more use cases (Thanks to @henhuy and
Kevin Abbott) - Corece float argument add to
to_timeseries()
method (Thanks Yousuf Jawwad)
0.4.3 (2017-06-02)
- Fix doc typos and formatting
- Prevent column duplication in read_frame (Thanks Kevin Abbott)
0.4.2 (2017-05-22)
- Compatibility with
pandas 0.20.1
- Support for Python 2.7 and 3.5 with Django versions 1.8+
- Suport for Python 3.6 and Django 1.11
- We still support legacy versions (Python 2.7 and Django 1.4)
0.4.1 (2016-02-05)
- Address the incompatibility with Django 1.9 due to the removal of
specialized query sets like the
ValuesQuerySet <https://code.djangoproject.com/ticket/24211>
_ - Address the removal of the
PassThrougManager
from django-model-utils
version 2.4
. We've removed the dependency on django-model-utils and
included the PassThroughManger (which was always a standalone tool
distributed a part of django-model-utils) for compatibility with
earlier versions of Django (<= 1.8). For more recent versions of
Django we're using Django's built in QuerySet.as_manager()
. - Now supports Pandas 0.14.1 and above
- The fall in Coverage in this release largely reflects the integration of
the PassThroughManager into the code base. We'll add the required test
coverage for the PassThroughManager in subsequent releases.
0.3.1 (2015-10-25)
- Extends the ability to span a ForeignKey relationship with double underscores
to OneToOneField too thanks to Safe Hammad
- Provide better support for ManyToMany and OneToMany relations thanks to
Jeff Sternberg and @MiddleFork
0.3.0 (2015-06-16)
- This version supports Django 1.8
- Support for Pandas 0.16
0.2.2 (2015-03-02)
- Added Support for Django 1.7
0.2.1 (2015-01-28)
- Added Support for Values QuerySets
- Support for Python 2.6
- Note we still have limited support for Django 1.7 but this will be coming in
the next release
0.2.0 (2014-06-15)
- Added the
io
module so that DataFrames can be created from any
queryset so you don't need to to add a DataFrame manager
to your
models. This is good for working with legacy projects. - added a Boolean
verbose
argument to all methods (which defaults to True
)
This populate the DataFrame columns with the human readable versions of
foreign key or choice fields. - Improved the performance DataFrame creation by removing dependency on
np.core.records.fromrecords
- Loads of bug fixes, more tests and improved coverage and better
documentation