Flask raises TemplateNotFound error even though template file exists

If you have encountered a TemplateNotFound error in Flask even though your template file exists, don’t worry, you are not alone. This is a common issue that many Flask developers face, but the good news is that there is a very simple solution to this problem.

The TemplateNotFound error is raised when Flask is unable to locate the specified template file. This can happen for a variety of reasons, but the most common cause is that the file path specified in the `render_template()` function is incorrect.

To fix this issue, first make sure that the template file is located in the correct directory within your Flask project. The standard practice is to store all template files in a folder named “templates” within the project’s root directory. If your template file is located elsewhere, you will need to specify the correct file path when calling the `render_template()` function.

For example, if your template file is located in a folder named “my_templates” within the project’s root directory, you would need to call the `render_template()` function like this:

return render_template('my_templates/my_template.html')

Alternatively, you can specify the absolute file path to the template file:

return render_template('/path/to/your/template/my_template.html')

Another common mistake that can lead to the TemplateNotFound error is using the wrong file extension for the template file. Make sure that your template file has the correct extension, such as .html, .jinja, or .xml, depending on the templating engine you are using.

Finally, if you are still encountering the TemplateNotFound error even though you have verified that the template file exists and the file path is correct, it is possible that Flask’s template caching mechanism is causing the issue. In this case, you can try clearing Flask’s template cache by restarting the development server or using a browser hard refresh (Ctrl + F5).

In conclusion, if you are receiving a TemplateNotFound error in Flask even though your template file exists, double-check the file path and file extension, and clear Flask’s template cache if necessary. By following these simple steps, you should be able to resolve the issue and get back to developing your Flask application without any further trouble.