document __version__ module member and version check

doc/src/Python_module.rst

@@ -26,6 +26,23 @@ There are multiple Python interface classes in the :py:mod:`lammps` module:
 
 .. _mpi4py_url: https://mpi4py.readthedocs.io
 
+.. admonition:: Version check
+   :class: note
+
+   The :py:mod:`lammps` module stores the version number of the LAMMPS
+   version it is installed from.  When initializing the
+   :py:class:`lammps <lammps.lammps>` class, this version is checked to
+   be the same as the result from :py:func:`lammps.version`, the version
+   of the LAMMPS shared library that the module interfaces to.  If the
+   they are not the same an AttributeError exception is raised since a
+   mismatch of versions (e.g.  due to incorrect use of the
+   ``LD_LIBRARY_PATH`` or ``PYTHONPATH`` environment variables can lead
+   to crashes or data corruption and otherwise incorrect behavior.
+
+.. automodule:: lammps
+   :members:
+   :noindex:
+
 ----------
 
 The ``lammps`` class API

doc/src/fix_flow_gauss.rst

@@ -165,8 +165,9 @@ LAMMPS was built with that package.  See the :doc:`Build package
 Related commands
 """"""""""""""""
 
-:doc:`fix addforce <fix_addforce>`, :doc:`compute temp/profile
-     <compute_temp_profile>`, :doc:`velocity <velocity>`
+:doc:`fix addforce <fix_addforce>`,
+:doc:`compute temp/profile <compute_temp_profile>`,
+:doc:`velocity <velocity>`
 
 Default
 """""""

python/lammps/__init__.py

@@ -1,3 +1,13 @@
+"""
+LAMMPS module global members:
+
+.. data:: __version__
+
+   Numerical representation of the LAMMPS version this
+   module was taken from.  Has the same format as the
+   result of :py:func:`lammps.version`.
+"""
+
 from .constants import *
 from .core import *
 from .data import *