What is a Flask?
Once you have Python installed, you can install and configure pip, setuptools and virtualenv.
pip is a recommended tool for installing Python packages.
How to install pip?
The most secure way to install pip on your machine is by downloading get-pip.py and run the following command, which may require administrator / root rights:
How to upgrade pip?
Once installed, it is very easy to upgrade pip to a newer version:
pip install -U pip
Follow the solutions explained in the following blog post.
setuptools is a library used for packaging Python projects that allows easily to download, build, install, uninstall and upgrade these Python packages.
How to install setuptools?
pip install setuptools
virtualenv is a very helpful tool, used to keep the Python project dependencies in different places, allowing to build isolated environments. It solves dependency, versioning and permissions issues, where common packages are shared between multiple projects.
How to install virtualenv?
pip install virtualenv
virtualenvwrapper is set of extensions for the virtualenv tool, which allows easily to create, used and delete virtual environments.
How to install and configure virtualenvwrapper on UNIX systems?
pip install virtualenvwrapper
… and configuration is done like this …
export WORKON_HOME=~/Envs mkdir -p $WORKON_HOME source /usr/local/bin/virtualenvwrapper.sh
How to install and configure virtualenvwrapper on Windows systems?
pip install virtualenvwrapper-win
Create a new virtual environment
Now you could install some Python packages:
(flask_env)$ pip install flask
Activate a virtual environment
Deactivate the current virtual environment and switch back to the default one
More virtualenvwrapper commands can be found here.
My First Flask Application
Now that you have pip, setuptools and virtualenv installed and configured, you could implement your first Flask application.
First you should activate the already created virtual environment:
Create a new python module named app.py and paste the following code within it:
Run the following command to start the flask application:
Open your browser and type http://localhost:5000 By default the flask web application will run on port 5000. You could change that option by specifying the port parameter of the run method:
In the next blog post I will write how to structure your Flask project.