Python Data Analysis Library

pandas is an open source, BSD-licensed library providing high-performance, easy-to-use data structures and data analysis tools for the Python programming language.

pandas is a NUMFocus sponsored project. This will help ensure the success of development of pandas as a world-class open-source project, and makes it possible to donate to the project.

v0.21.1 Final (December 12, 2017)

This is a minor bug-fix release in the 0.21.x series and includes some small regression fixes, bug fixes and performance improvements. We recommend that all users upgrade to this version.

Highlights include:

• Temporarily restore matplotlib datetime plotting functionality. This should resolve issues for users who relied implicitly on pandas to plot datetimes with matplotlib. See here.
• Improvements to the Parquet IO functions introduced in 0.21.0. See here.

See the v0.21.1 Whatsnew overview for an extensive list of all the changes for 0.21.1.

v0.21.0 Final (October 27, 2017)

This is a major release from 0.20.3 and includes a number of API changes, deprecations, new features, enhancements, and performance improvements along with a large number of bug fixes. We recommend that all users upgrade to this version.

Highlights include:

• Integration with Apache Parquet, including a new top-level read_parquet function and DataFrame.to_parquet method, see here.
• New user-facing dtype pandas.api.types.CategoricalDtype for specifying categoricals independent of the data, see here.
• The behavior of sum and prod on all-NaN Series/DataFrames is now consistent and no longer depends on whether bottleneck is installed, see here.
• Compatibility fixes for pypy, see here.
• Additions to the drop, reindex and rename API to make them more consistent, see here.
• Addition of the new methods DataFrame.infer_objects (see here) and GroupBy.pipe (see here).
• Indexing with a list of labels, where one or more of the labels is missing, is deprecated and will raise a KeyError in a future version, see here.

Check the API Changes and deprecations before updating.

Best way to Install

The best way to get pandas is via conda

conda install pandas

Packages are available for all supported python versions on Windows, Linux, and MacOS.

Wheels are also uploaded to PyPI and can be installed with

pip install pandas

Quick vignette

10-minute tour of pandas from Wes McKinney on Vimeo.

What problem does pandas solve?

Python has long been great for data munging and preparation, but less so for data analysis and modeling. pandas helps fill this gap, enabling you to carry out your entire data analysis workflow in Python without having to switch to a more domain specific language like R.

Combined with the excellent IPython toolkit and other libraries, the environment for doing data analysis in Python excels in performance, productivity, and the ability to collaborate.

pandas does not implement significant modeling functionality outside of linear and panel regression; for this, look to statsmodels and scikit-learn. More work is still needed to make Python a first class statistical modeling environment, but we are well on our way toward that goal.

What do our users have to say?

Roni Israelov, PhD

Portfolio Manager

AQR Capital Management

“pandas allows us to focus more on research and less on programming. We have found pandas easy to learn, easy to use, and easy to maintain. The bottom line is that it has increased our productivity.”

David Himrod

Director of Optimization & Analytics

AppNexus

“pandas is the perfect tool for bridging the gap between rapid iterations of ad-hoc analysis and production quality code. If you want one tool to be used across a multi-disciplined organization of engineers, mathematicians and analysts, look no further.”

Olivier Pomel

CEO

Datadog

“We use pandas to process time series data on our production servers. The simplicity and elegance of its API, and its high level of performance for high-volume datasets, made it a perfect choice for us.”

Library Highlights

• A fast and efficient DataFrame object for data manipulation with integrated indexing;
• Tools for reading and writing data between in-memory data structures and different formats: CSV and text files, Microsoft Excel, SQL databases, and the fast HDF5 format;
• Intelligent data alignment and integrated handling of missing data: gain automatic label-based alignment in computations and easily manipulate messy data into an orderly form;
• Flexible reshaping and pivoting of data sets;
• Intelligent label-based slicing, fancy indexing, and subsetting of large data sets;
• Columns can be inserted and deleted from data structures for size mutability;
• Aggregating or transforming data with a powerful group by engine allowing split-apply-combine operations on data sets;
• High performance merging and joining of data sets;
• Hierarchical axis indexing provides an intuitive way of working with high-dimensional data in a lower-dimensional data structure;
• Time series-functionality: date range generation and frequency conversion, moving window statistics, moving window linear regressions, date shifting and lagging. Even create domain-specific time offsets and join time series without losing data;
• Highly optimized for performance, with critical code paths written in Cython or C.
• Python with pandas is in use in a wide variety of academic and commercial domains, including Finance, Neuroscience, Economics, Statistics, Advertising, Web Analytics, and more.