{"id":2508,"date":"2020-12-21T17:20:25","date_gmt":"2020-12-21T22:20:25","guid":{"rendered":"https:\/\/kb.n0c.com\/?post_type=ht_kb&p=2508"},"modified":"2026-02-06T14:31:25","modified_gmt":"2026-02-06T19:31:25","slug":"python-application-management","status":"publish","type":"ht_kb","link":"https:\/\/kb.n0c.com\/en\/knowledge-base\/python-application-management\/","title":{"rendered":"How to Manage Python Applications"},"content":{"rendered":"\n

Introduction<\/strong><\/h2>\n\n\n\n

Python is essentially code executed on our servers to host, create and control web applications using this type of language.<\/p>\n\n\n\n

In this article, we will focus on information for beginners. We will start by explaining how to access Python in N0C and provide a detailed example of how to launch and modify an application using this interface. <\/p>\n\n\n\n

Then, for more advanced users, we will explain how to do the same operations in command line.<\/p>\n\n\n\n

Note :<\/strong> The Glossary of N0C<\/a> contains explanations on multiple topics and can be consulted to clarify certain terms.<\/p>\n\n\n\n

Documentation<\/strong><\/h2>\n\n\n\n

Documentation on Python can be found on the Web, in particular at: https:\/\/docs.python.org\/3\/<\/a>.<\/p>\n\n\n\n

You can refer to this site to get more information about the commands of the Python Selector<\/strong>: https:\/\/docs.cloudlinux.com\/command-line_tools\/#new-python-selector<\/a>.<\/p>\n\n\n\n

Debugging an Application<\/h3>\n\n\n\n

When an error occurs, a page like the one below is displayed:<\/p>\n\n\n

\n
\"\"<\/a><\/figure><\/div>\n\n\n

This page is not very explanatory. Activating the development mode allows you to investigate (please refer to the article How to Debug a Node.js, Ruby or Python Application<\/a>).<\/p>\n\n\n\n

Prerequisite<\/strong><\/h2>\n\n\n\n

Go to https:\/\/mg.n0c.com\/en\/<\/a>.<\/p>\n\n\n\n

Access to Python<\/strong> in N0C<\/h2>\n\n\n\n
    \n
  1. In the Sidebar menu, select Languages<\/strong> > Python<\/strong>.<\/li>\n\n\n\n
  2. Applications already set up are displayed in the interface:<\/li>\n<\/ol>\n\n\n
    \n
    \"\"<\/a><\/figure><\/div>\n\n\n

    Implementation of a New Python Application with N0C<\/strong><\/strong><\/h2>\n\n\n\n

    To explain the approach more easily, we will proceed with an example.  <\/p>\n\n\n\n

    Let\u2019s say you want to create the run.py<\/strong> application that displays the words “Hello World!”. The following steps are necessary:<\/p>\n\n\n\n

      \n
    1. First of all, you have to create an application<\/strong> in the directory intended to contain it (we will call this directory \u201ccodepython<\/strong>\u201d as an example, but the user can give it the name they desire). When it is executed, the application displays the words \u201cIt works!\u201d.<\/li>\n\n\n\n
    2. You then need to program<\/strong> it (in our example, to display “Hello World!”).<\/li>\n\n\n\n
    3. Then, call<\/strong> the application environment. <\/li>\n\n\n\n
    4. Finally, you have to activate<\/strong> the Python environment.<\/li>\n<\/ol>\n\n\n\n

      Step #1 – Create the Python Application<\/strong><\/h3>\n\n\n\n

      Make sure the codepython<\/strong> directory is created (please refer to the article How to Use the File Manager<\/a>).<\/p>\n\n\n\n

        \n
      1. Click on the Create<\/strong> button:<\/li>\n<\/ol>\n\n\n
        \n
        \"\"<\/a><\/figure><\/div>\n\n\n
          \n
        1. Choose the desired VERSION<\/strong> of Python:<\/li>\n<\/ol>\n\n\n
          \n
          \"\"<\/a><\/figure><\/div>\n\n\n
            \n
          1. Indicate in which APP DIRECTORY<\/strong> you want the application to be created (in our example, we would write codepython<\/strong>).<\/li>\n\n\n\n
          2. Indicate from which APPLICATION DOMAIN\/URL<\/strong> the application should be accessible (in our example, we would write codepython<\/strong>).<\/li>\n\n\n\n
          3. Enter the name of the BOOT FILE<\/strong> (optional).<\/li>\n\n\n\n
          4. Click on the CREATE<\/strong> button.<\/li>\n\n\n\n
          5. Confirm the creation of run.py<\/strong> and passenger_wsgi.py<\/strong>1<\/sup> by opening the codepython<\/strong> directory in the File Manager<\/strong> (please refer to the article How to Use the File Manager<\/a>).<\/li>\n\n\n\n
          6. Test the Python application by typing https:\/\/DOMAIN\/codepython<\/strong> in your browser, DOMAIN<\/strong> having to be replaced by your real domain name.<\/li>\n\n\n\n
          7. The result is (as expected): “It works!”.<\/li>\n<\/ol>\n\n\n\n

            Step #2 – <\/strong>Program the Application<\/h3>\n\n\n\n

            Now that the Python application is installed and functional in the directory to be used, you can program it as we wish. The application must be started again to see the modifications in the browser when it is exectued. <\/p>\n\n\n\n

            Here are the steps to program:<\/p>\n\n\n\n

              \n
            1. In the File Manager<\/strong>, open the directory (in our example, codepython<\/strong>) and edit the code run.py<\/strong> (please refer to the article How to Use the File Manager<\/a>).<\/li>\n\n\n\n
            2. Program run.py<\/strong>. In our example, copy the following code in the programming window of the File Manager<\/strong> (please refer to the article How to Use the File Manager<\/a>), so that the words “Hello World!<\/strong>” are displayed when you run codepython<\/strong> on your domain:<\/li>\n<\/ol>\n\n\n\n
              import os\nimport sys\n\nsys.path.insert(0, os.path.dirname(__file__))\n\ndef app(environ, start_response):\n     start_response('200 OK', [('Content-Type', \u2018text\/plain')])\n     message = 'Hello World!n\u2019\n     version = 'Python %sn' % sys.version.split()[0]\n     response = 'n'.join([message, version])\n     return [response.encode()] <\/pre>\n\n\n\n
                \n
              1. After having saved the code, close and open N0C again to apply the changes.<\/li>\n\n\n\n
              2. Test the Python application by typing https:\/\/DOMAIN\/codepython<\/strong> in your browser, DOMAIN<\/strong> having to be replaced by your real domain name.<\/li>\n\n\n\n
              3. The result shall now be “Hello  World!”.<\/li>\n<\/ol>\n\n\n\n
                Step #3 \u2013 Call the Environment of the Application<\/h3>\n\n\n\n
                Before performing any other command, you must call the application environment by running the following command at the root of your application, which will set the environment variables and allow you to configure your application:<\/p>\n\n\n
                \n
                \"\"<\/a><\/figure><\/div>\n\n\n
                The command must be copied into the shell of the account in question. It is possible to connect via SSH.<\/p>\n\n\n\n
                To see the command, you must edit the application (please refer to the paragraph Python Application Settings Modification<\/strong>).<\/p>\n\n\n\n
                Therefore, in our example, the command to be copied is :<\/p>\n\n\n\n
                source \/home\/fbkfdayw\/virtualenv\/codepython\/3.8\/bin\/activate<\/pre>\n\n\n\n
                Where :<\/p>\n\n\n\n