readline Python module missing in linux release

From Santiago Serebrinsky sserebrinsky@gmail.com on paraview@paraview.org:

I am under Ubuntu 16.04 LTS.

I have currently two versions of Paraview:

1. Paraview 5.0.1, installed with apt-get. It is using Python 2.7.12.
2. ParaView-5.4.1-Qt5-OpenGL2-MPI-Linux-64bit, simply expanded. It uses Python 2.7.11.

When I use version 2 of pvpython (~/apps/ParaView-5.4.1-Qt5-OpenGL2-MPI-Linux-64bit/bin/pvpython) I get the error

    import readline
ImportError: No module named readline

from my ~/.pythonrc.

In version 1 of pvpython, readline resides in /usr/lib/python2.7/lib-dynload

>>> readline.__file__
'/usr/lib/python2.7/lib-dynload/readline.x86_64-linux-gnu.so'

In version 2 readline is not present anywhere in ~/apps/ParaView-5.4.1-Qt5-OpenGL2-MPI-Linux-64bit/

Why is this? Can it be fixed?

PS: directory ~/apps/ParaView-5.4.1-Qt5-OpenGL2-MPI-Linux-64bit/lib/python2.7/lib-dynload (where I expected to find readline given version 1) is empty. Many of the modules which in version 1 reside in /usr/lib/python2.7/lib-dynload, are present in lib/python2.7, not in lib/python2.7/lib-dynload, in version2:

>>> import parser
>>> parser.__file__
'/home/santiago/apps/ParaView-5.4.1-Qt5-OpenGL2-MPI-Linux-64bit/lib/python2.7/parser.so'

But readline is an exception here.