ActiveState has made it easy to install the latest version of Flask. Copy and paste the snippet below into your terminal to install a verified, built-from-source version of Flask from ActiveState's free repository. We've taken care of all the dependencies so you don't have to.
pip3 install --index-url https://har.activestate.com/activestate/trusted-artifacts/latest flask==2.0.2
--index-url parameter tells pip to install the package from ActiveState's repository.
Built from source code
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Support for OS-level dependencies
Artifact dependencies extend to the operating-system level. For example, when building XML libraries for Python, we also build Expat from its C source files.
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Source is updated as new versions are released, but after a manual and automatic review process and at 24-48 hour delay compared to the main public repository.
Artifacts built for Linux, MacOS, Windows
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We store all provenance metadata available for all artifacts, exposing it as machine-readable SBOM files.
Supply chain levels for Software Artifacts (SLSA) Level 4
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ActiveState's mission is to make open source easy and safe for everyone. We believe in baking security and compliance right into the source code so you start with a clean slate before you code line 1.
You can download trusted versions of open source artifacts from our repository, or sign up for free for the ActiveState platform in order to create a secure Python environment that contains just the packages your project requires – all built from source code for Linux, Windows and macOS.
For more than 20 years, ActiveState has been making open source easier, more secure, and less risky.
Flask is a web framework written in Python that lets you easily develop web applications. The two most popular frameworks for Python, Django and Flask, take incredibly different approaches to web development. Django, the older of the two frameworks, is often called a “batteries included” framework, meaning that it contains just about everything you need to launch a full featured application in no time flat. Flask, on the other hand, is a highly extensible “microframework” that launches with a bare minimum set of features, but has a thriving plugin ecosystem which allows developers to only include the functionality that they need to succeed.
Flask is based on the Werkzeug WSGI toolkit and the Jinja2 template engine and is considered very Pythonic, meaning it follows the conventions of the Python community and uses the language as intended. It’s explicit and readable.
Flask is compatible with Python 3.7 and up. Flask is not compatible with Python 2.
Flask has the following dependencies, which will be installed automatically when installing Flask.
Copy (either ctrl+c or just click the “copy” button) and paste the snippet at the top of this page into your command line. As with all Python packages installed with Python’s default package manager, pip, Flask will be installed to %PYTHONHOME%/site-packages.
You can also work in a virtual environment to prevent conflicts. You can use pip to install a specific version of the Flask package into a virtual environment for Python 3 projects with the following command:
python3 -m venv <path_to_env>
venv will create a virtual Python installation in the <env_name> folder.
Activate <env_name> with the following command:
You can pip install Flask into your virtual environment with the following command:
python -m pip install flask
If you want to create a development server on your local computer, you can do so easily. Save your program as server.py and run it with python server.py.
$ python server.py * Serving Flask app "hello" * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
As with all Python packages installed with pip, Flask will be installed to %PYTHONHOME%/site-packages. This will install Flask globally. However, we always recommend installing into a virtual environment (like virtualenv).
While Flask will work on Windows, Mac & Linux (Ubuntu, CentOS, RHEL, etc.), our implementation currently does not support Mac deployments.
Flask makes it easy to build web applications since you can build a Flask application quickly using only a single Python file. It’s great for both beginner and complex use cases.
For example, you can create the “Hello World” application in your development environment as a simple Flask application with the following code:
from flask import Flask app = Flask(__name__) @app.route('/') def hello_world(): return 'Hello World!' if __name__ == '__main__': app.run()