PyCharm 2020.2 Help

Creating a Flask Project

Flask project in intended for productive development of the Flask applications. PyCharm takes care of creating the specific directory structure, and settings.

To create a Flask project, follow these steps

  1. From the main menu, choose File | New Project..., or click the New Project button in the Welcome screen. New Project dialog opens.

    Create a Flask project

  2. In the New Project dialog, do the following:

    • Specify project type Flask.

    • Specify project location.

  3. Next, click Expand the node to expand the Python Interpreter node, and select the new environment or existing interpreter, by clicking the corresponding radio-button.

    The following steps depend on your choice:

    • New environment using: if this option has been selected, choose the tool to be used to create a virtual environment. To do that, click the list and choose Virtualenv , Pipenv , or Conda .

      Next, specify the Location and Base interpreter of the new virtual environment. If necessary, click the Inherit global site-packages and Make available to all projects check boxes.

      When configuring the base interpreter, you need to specify the path to the Python executable. If PyCharm detects no Python on your machine, it provides two options: to download the latest Python versions from python.org or to specify a path to the Python executable (in case of non-standard installation).

      Downloading Python when creating a new project
    • Existing interpreter: if this option has been selected, choose the desired interpreter from the list, or (if the desired interpreter is not found), click Open and choose the interpreter. See Configure a Python interpreter for details.

  4. Click More settings (More Settings), and specify the following:

    • From the Template language list, select the language to be used.

    • In the Templates folder field, specify the directory where the templates will be stored, and where they will be loaded from. You can specify the name of the directory that doesn't yet exist; in this case, the directory will be created.
  5. Click Create.

PyCharm creates an application and produces specific directory structure, which you can explore in the Project tool window. Besides that, PyCharm creates a stub Python script with the name app.py, which provides a simple "Hello, World!" example.

You can run the created application by pressing Shift+F10 Preview the run results.

Run Flask app

Note that the application was run with the following Flask specific variables:

  • FLASK_APP=app.py – Defines an entry point of the Flask application - the target instance of the Flask class. When extending your Flask application and adding more modules and files, you might need to pass some non-default FLASK_APP values. You can pass a module name, a path to the target Python file, or any combination of modules, scripts, and Flask class instances, for example, FLASK_APP=access_management.access:app2, where:

    • access_management – the module name

    • access – the target file in the module

    • app2 – the Flask class instance in access.

    For more information about the FLASK_APP variable, refer to Flask CLI documentation.

  • FLASK_ENV=development – Sets one of possible environments.

  • FLASK_DEBUG=0 – Controls the built-in Flask debug mode. With this mode enabled FLASK_DEBUG=1, the development server will be automatically reloaded on any code change enabling continuous debugging. For more information about Flask debugger, refer to Flask Debug Mode.

You can change Flask specific variables by editing the corresponding parameters of the Flask Server Run/Debug configuration.

When you've enabled Flask support in your project, the Python console starts acting as a Flask console. Use code completion to enter and execute Flask-specific commands.

Flask console

Last modified: 03 September 2020