... main()

For a package, the same effect can be achieved by including a __main__.py module, the contents of which will be executed when the moduleis runwith-m

For a package, the same effect can be achieved by including a __main__.py module, the contents of which will be executed when the moduleis runwith-m.

For example we are developing script whichis designed to be usedas module, we should do:

3. Python files can actas either reusable modules,oras standalone programs.

4.if`__name__== “main”:`is used to execute some code onlyif thefile was run directly,andnot imported.

The setup scriptis the centre ofall activityin building, distributing,and installing modules using the Distutils. The main purpose of the setup scriptis to describe your module distribution to the Distutils, so that the various commands that operate on your modules do the right thing.

The`setup.py`fileis at the heart of a Python project. It describesall of the metadata about your project. There a quite a few fields you can add to a project to give it a richset of metadata describing the project. However, there are only three required fields: name, version,and packages. The name field must be uniqueif you wish to publish your package on the Python Package Index (PyPI). The version field keeps track of different releases of the project. The packages field describes where you’ve put the Python source code within your project.

This allows you to easily install Python packages. Often it's enough to write:

$ python setup.py install

and module will install itself.

Our initial setup.py will also include information about thelicenseand will re-use theREADME.txtfilefor the long_description field. This will look like:

>>>from distutils.coreimport setup

>>> setup(

...name='pythonCheatsheet',

...version='0.1',

...packages=['pipenv',],

...license='MIT',

...long_description=open('README.txt').read(),

... )

Find more information visit http://docs.python.org/install/index.html.

The use of a Virtual Environmentis to test python codein encapsulated environmentsand to also avoid filling the base Python installationwith libraries we might usefor only one project.