Internationalization and Localization
Web applications are usually not limited to one geographical region or only serve people from one linguistic domain. For example, a web application intended for users in Europe will be expected to support more than one European language, such as German, French, Italian, and Spanish, as well as English. This chapter will cover the basics of how to enable support for multiple languages in a Flask application.
Adding support for a second language in any web application is a tricky affair. It increases the overhead a bit every time some change is made to the application, and this increases with the number of languages. There can be a number of things that need to be taken care of, apart from just changing the text, depending on the language. Some of the major things that need changing are currency, number, time, and date formatting.
Flask-Babel, an extension that adds internationalization (i18n) and localization (l10n) support to any Flask application...