Flask downloads text file instead of pythonf ile

The path should be relative from the reports directory saved in our app. Likewise any non-existent filenames would throw a error. The reason? I'm sure you wouldn't want users to be able to downlaod any file from your application at their own will. Read more about sending files in Flask over at the official documentation, linked here. Drop the app. Using the sass, rcssmin and rjsmin Python packages to optimize web assets, including Bootstrap.

Using Python decorators to add another layer of functionality to Flask routes. Home Articles Categories Series. Recommended learning Pluralsight Treehouse. Sending files with Flask Learning Flask Ep. Let's get started. Flask imports First up, we're going to need some imports from flask. The absolute path of the directory containing images for users to download app.

The pathlib method. If False is returned, no file with that name exists in that location. Sweigart explains the readlines method page , but he does not cover the readline method, which reads exactly one line at a time.

These two different methods can come in handy for solving different problems. In the following example, first we write two new lines into a new file. Then we read them, one at a time, with readline :. Compare that with this example, using readlines :. When you call readlines on a file, it returns a Python list that contains each line in the file as a list item.

You can then loop over the list, search the items, sort them, etc. This comes in handy if you have a file open for reading and you have come to the bottom of it. Calling seek 0 on the File object returns to the top of the file so you can read it or search its contents again. To create a Python list from a file, use readlines.

In this example, we have a plain-text file that contains four items of information about each U. In each line, the four items are separated by tabs. So we want to get this:. This value is used to prevent malicious hijacking of your form from an outside submission. You can read more about app. Python style dictates that a class starts with an uppercase letter and uses camelCase , so here our new class is named NameForm we will use the form to search for a name. In the class, we assign each form control to a unique variable.

This form has only one text input field and one submit button. Learn more about classes in Python here. If you had more than one form in the app, you would define more than one new class in this manner. Note that StringField and SubmitField were imported at the top of the file. If we needed other form-control types in this form, we would need to import those also. See a list of all WTForms field types. Within the list, each choice is a pair in this format: 'string1', 'string2'.

WTForms also has a long list of validators we can use. The DataRequired validator prevents the form from being submitted if that field is empty.

Note that these validators must also be imported at the top of the file. Be aware that if we had created more than one form class, each of those would need to be assigned to a unique variable.

Where is the form? This is the amazing thing about Flask-WTF — by configuring the form as we did in the Flask app, we can generate a form with Bootstrap styles in HTML using nothing more than the template you see above. Line 27 is the form.

Note that in the Flask route function, we passed the variable form to the template index. So when you use wtf. We discussed the configuration of NameForm above. Below that, you wrote Bootstrap app in the Flask app file.

That combination of four things has embedded Bootstrap 4 in this app and made wtf. You can, of course, use Flask-Bootstrap4 without the forms! Before reading further, try out a working version of this app. Otherwise, you stay on the same page, the form is cleared, and a message tells you that actor is not in the database. First we have the route, as usual, but with a new addition for handling form data: methods. GET simply requests a response from the server. POST , however, sends a request with data attached in the body of the request; this is the way most web forms are submitted.