Due to different sorting behaviour in Python 2 and 3, the found symmetry
groups might differ while still being conceptually correct. Instead of
expecting exact results, the unit test now only checks for the number
of found groups and their size. Size is checked on the first element,
equal size of those elements is checked elsewhere.

import_array() must be called when the numpy C-API is called.
This is a macro that in our case defined a return value that makes
the compiler complain. The added #define statement enforces no return value

- Fix python code that is injected into python interpreter
- Proper error handling => fatal_error to stop cmake run if numpy not found

This can happen if python has been compiled with a specialized
malloc.

In Python 2, this assignment had the effect that the whole property
(and it's lazy evaluation functionality) was completely overwritten
and the private _chain_mapping was useless afterwards. Python 3 raises
an AttributeError instead ("can't set attribute").

python 2: [1,2,3,4,5,6] >= whatever_int => True
python 3: [1,2,3,4,5,6] >= whatever_int => TypeError

checked with: https://github.com/realbigws/DeepAlign
commit: cff7c39c89c6706858532b55567083823a0f2657

This enables string encoding in passed streams => stdout and stderr

This enables string encoding in passed streams => stdout and stderr

This enables string encoding in passed streams => stdout and stderr

This enables string encoding in passed streams => stdout and stderr

This enables string encoding in passed streams => stdout and stderr

This enables string encoding in passed streams => stdout and stderr

This enables string encoding in passed streams => stdout and stderr

Executed command: 2to3-2.7 -n -w actions/ost-compare-structures

execfile has been replaced by exec in Python 3

Previously we only had next, which is Python 2 compatible. Now
we have both.

in Python 2: 1/2=0 in Python 3: 1/2 = 0.5

Python 3 rounds towards the nearest even number if its in the middle
of two integers as opposed to Python 2 that simply rounds to the higher
integer number. By doing that we avoid biases towards higher numbers.

A simple function returing True or False is also not sufficient anymore.
functools.cmp_to_key comes to the rescue.

Python 2 allows for boolean comparisons with None, Python 3 does not.

That's the Python modules we generate with boost.python. 2to3 misses them

Executed command: 2to3-2.7 -n -w scripts/ost_startup.py.in

This commit doesn't make OpenStructure work with Python 3. The goal of this
commit was to perform an automated port of the Python code and make it compile.
The performed steps:

- Edited CMakeLists.txt to search for Python with 3.6 as min version 3.6 is the
  Python version shipped by default with Ubuntu 18.04 LTS
- Add version 3.6 to cmake_support/FindPython.cmake
- Adapt setup_boost macro in cmake_support/OST.cmake to prefer versioned
  libraries and not first check for boost_python.so. In the example of
  Ubuntu 18.04, libboost_python.so is specific for Python 2 but
  libboost_python3.so is the one we want.
- apply the following command: 2to3-2.7 -n -w <OST_DIR>
- adapt base/pymod/wrap_base.cc, gui/pymod/wrap_gui.cc and
  gui/pymod/export_message_widget.cc as PyString functionalities do not exist
  anymore in the Python 3 interpreter (replaced by PyUnicode)
- adapt gui/src/python_shell/python_interpreter_worker.hh to resolve issue
  discussed in https://stackoverflow.com/questions/23068700/embedding-python3-in-qt-5
  Long story short: Qt does a typedef for "slots" which causes trouble with
  other headers that are pulled in from the Python interpreter