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

From the main menu, choose File | New Project..., or click the New Project button in the Welcome screen. New Project dialog opens.
In the New Project dialog, do the following:
- Specify project type Flask.
- Specify project location.
Next, click to expand the Python Interpreter node, and select the new environment or previously configured 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.
  Select the Inherit global site-packages checkbox if you want that all packages installed in the global Python on your machine to be added to the virtual environment you're going to create. This checkbox corresponds to the --system-site-packages option of the virtualenv tool.
  Select the Make available to all projects checkbox if you want to reuse this environment when creating Python interpreters in PyCharm.
  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).
- Previously configured interpreter: if this option has been selected, choose the desired interpreter from the list, or (if the desired interpreter is not found), click and choose the interpreter. See Configure a Python interpreter for details.
  When PyCharm stops supporting any of the outdated Python versions, the corresponding Python interpreter is marked as unsupported.
Click (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.
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.

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.

Last modified: 27 August 2021