ChemApp for Python with a Bare Python Installation
**************************************************
This procedure explains how to install ChemApp for Python into a bare Python
installation.

Windows
~~~~~~~

#. Download the relevent version of Python. For the current ChemApp for Python
   version, you need to download `Python 3.9.1. <https://www.python.org/ftp/python/3.9.1/python-3.9.1-amd64.exe>`_.

#. Install Python.

   Double-click on the downloaded ``python-3.9.5-amd64`` file. In the
   installation window, tick the "Add Python 3.9 to PATH" and choose customise
   installation and click next. On the Optional Features window, make sure that
   all of the checkboxes are ticked and as seen in the Figure below, and click
   next.

       .. image:: figures/python-installation-1.jpg
        :align: center
        :scale: 65 %

   On the Advanced Options window seen in the Figure below, click on the
   "Install for all users" checkbox. This will change the install directory to
   ``C:\Program Files\Python39``. This should be changed to
   ``C:\Python39`` for simplification purposes.

       .. image:: figures/python-installation-2.jpg
        :align: center
        :scale: 65 %

   After the installation, the window can be closed.

#. Additional installations.

   To be able to install the ChemApp for Python package, ``setuptools`` and
   ``pip`` (a Python package manager) must be installed. These are installed by
   entering the following commands into the ``Command Prompt``. The command
   prompt can be opened by pressing ``Windows-R`` (hold down the Windows key and
   press ``R``), typing ``cmd``, and pressing ``Enter``.

   #. install pip:

      .. code-block:: bat

         curl https://bootstrap.pypa.io/get-pip.py | python

   #. install setuptools:

      .. code-block:: bat

         pip install setuptools


      If you are unsuccessful with the installation, a more detailed procedure
      can be found `here
      <https://stackoverflow.com/questions/1449494/how-do-i-install-python-packages-on-windows>`_.
      Or consider to switch to one of the IDE installation methods.

#. Install new packages using ``pip``.

   In the command prompt, new packages can be installed with the following
   command: ``pip install <new-package>``. Try it out by installing the numpy
   package:

   .. code-block:: bat

      pip install numpy

#. Display packages installed on Python.

   The following command can be used to see the packages installed on Python.

   .. code-block:: bat

      pip list

#. Download ChemApp for Python's free Light edition.

   ChemApp for Python Light can be downloaded from the GTT website. The
   dowloaded file should be stored in an easily accessible location. In this
   example, the file is downloaded to

   .. code-block:: bat

      C:\Python36\Scripts\python-packages\

   The "python-packages" folder was created manually.

#. Install ChemApp for Python Light.

   In the command prompt, type-in the following command to install ChemApp for Python
   Light

   .. code-block:: bat

      pip install C:\Python36\Scripts\python-packages\chemapp-0.3.2-gtt-win-chemapp7.2.0-python3.6.2.tar.gz

   The name of the downloaded file could differ depending on the ChemApp for Python
   release version.

#. Open python.

   Python can be opened by typing "python" in the command prompt. An
   alternative method is to press the ``Windows`` button,
   search for "python" and clicking on "Python 3.9 (64-bit)" under Apps.


Linux
~~~~~
The following procedure must be used to use ChemApp for Python in bare Python.

#. Install Python.

   Install Python 3.9 through the terminal with the following command:

   .. code-block:: bat

      sudu apt-get install python3

   Ensure that Python 3.9.1 is installed by downloading it
   `here <https://www.python.org/ftp/python/3.9.1/Python-3.9.1.tgz>`_. Unzip the
   file, with a name like ``Python-3.9.1.tgz`` in an easy to locate location.
   Then ``cd`` to the ``Python-3.9.1`` file in the terminal and run the
   following commands:

   .. code-block:: bat

      sudo make

   And,

   .. code-block:: bat

      sudo make install

   Verify that Python 3.9.1 was installed correctly by executing the following
   command:

   .. code-block:: bat

      python3 -V

#. Install ChemApp for Python.

   For this installation it is required to have obtained the ChemApp for Python
   ``*.tar.gz`` file. ``cd`` to where the ChemApp for Python package is stored and
   install ChemApp for Python through the terminal with the following command:

   .. code-block:: bat

      pip install chemapp_816-linux-chemapp_8.1.6-python3.9.1.tar.gz

   Ensure that ChemApp for Python installed successfully by running the following
   command in the terminal:

   .. code-block:: bat

      pip list

   A list of all the installed packages will appear. Below is an example of
   the list showing that ``chemapp`` is installed.

   .. code-block:: bat

      certifi                            2017.7.27.1
      cffi                               1.10.0
      chardet                            3.0.4
      chemapp                            816
      click                              6.7
      cloudpickle                        0.4.0
      clyent                             1.2.2
      colorama                           0.3.9

#. Running a Python file.

   In order to run a ``*.py`` file run the command, shown below, in therminal.
   The ``file_path`` to the ``*.py`` file must be entered correctly in the
   terminal.

   .. code-block:: bat

     python file_path/*.py