DOC: Add pint pandas ecosystem docs (#35170)

Author: znicholls

doc/source/ecosystem.rst

@@ -421,6 +421,14 @@ found in NumPy or pandas, which work well with pandas' data containers.
 Cyberpandas provides an extension type for storing arrays of IP Addresses. These
 arrays can be stored inside pandas' Series and DataFrame.
 
+`Pint-Pandas`_
+~~~~~~~~~~~~~~
+
+`Pint-Pandas <https://github.com/hgrecco/pint-pandas>` provides an extension type for
+storing numeric arrays with units. These arrays can be stored inside pandas'
+Series and DataFrame. Operations between Series and DataFrame columns which
+use pint's extension array are then units aware.
+
 .. _ecosystem.accessors:
 
 Accessors
@@ -436,10 +444,12 @@ Library         Accessor   Classes                   Description
 `cyberpandas`_  ``ip``     ``Series``                Provides common operations for working with IP addresses.
 `pdvega`_       ``vgplot`` ``Series``, ``DataFrame`` Provides plotting functions from the Altair_ library.
 `pandas_path`_  ``path``   ``Index``, ``Series``     Provides `pathlib.Path`_ functions for Series.
+`pint-pandas`_  ``pint``   ``Series``, ``DataFrame`` Provides units support for numeric Series and DataFrames.
 =============== ========== ========================= ===============================================================
 
 .. _cyberpandas: https://cyberpandas.readthedocs.io/en/latest
 .. _pdvega: https://altair-viz.github.io/pdvega/
 .. _Altair: https://altair-viz.github.io/
 .. _pandas_path: https://github.com/drivendataorg/pandas-path/
 .. _pathlib.Path: https://docs.python.org/3/library/pathlib.html
+.. _pint-pandas: https://github.com/hgrecco/pint-pandas

web/pandas/community/ecosystem.md

@@ -353,13 +353,22 @@ Cyberpandas provides an extension type for storing arrays of IP
 Addresses. These arrays can be stored inside pandas' Series and
 DataFrame.
 
+### [Pint-Pandas](https://github.com/hgrecco/pint-pandas)
+
+Pint-Pandas provides an extension type for storing numeric arrays with units.
+These arrays can be stored inside pandas' Series and DataFrame. Operations
+between Series and DataFrame columns which use pint's extension array are then
+units aware.
+
 ## Accessors
 
 A directory of projects providing
 `extension accessors <extending.register-accessors>`. This is for users to discover new accessors and for library
 authors to coordinate on the namespace.
 
-  | Library                                                     | Accessor |  Classes              |
-  | ------------------------------------------------------------|----------|-----------------------|
-  | [cyberpandas](https://cyberpandas.readthedocs.io/en/latest) | `ip`     | `Series`              |
-  | [pdvega](https://altair-viz.github.io/pdvega/)              | `vgplot` | `Series`, `DataFrame` |
+  | Library                                                       | Accessor |  Classes              |
+  | --------------------------------------------------------------|----------|-----------------------|
+  | [cyberpandas](https://cyberpandas.readthedocs.io/en/latest)   | `ip`     | `Series`              |
+  | [pdvega](https://altair-viz.github.io/pdvega/)                | `vgplot` | `Series`, `DataFrame` |
+  | [pandas_path](https://github.com/drivendataorg/pandas-path/)  | `path`   | `Index`, `Series` |
+  | [pint-pandas](https://github.com/hgrecco/pint-pandas)         | `pint`   | `Series`, `DataFrame` |