File uploads handling in Flask - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Flask class.

Flask

from flask import [1]

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AFlask

Brender_template

CRequest

Dredirect

Attempts:

3 left

💡 Hint

Common Mistakes

Importing Request instead of Flask

Using lowercase flask instead of Flask

The Flask class is imported from the flask module to create the app.

2fill in blank

medium

Complete the code to get the uploaded file from the request.

Flask

file = request.files.get('[1]')

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Adata

Bfilename

Cupload

Dfile

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'filename' which is a property, not the input name

Using 'upload' or 'data' which are not standard input names

The key used to get the uploaded file from request.files should match the form input name, commonly 'file'.

3fill in blank

hard

Fix the error in saving the uploaded file securely.

Flask

filename = [1](file.filename)
file.save(filename)

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Aos.path.basename

Bsecure_filename

Cstr

Dfile.filename.upper

Attempts:

3 left

💡 Hint

Common Mistakes

Saving file.filename directly without sanitizing

Using str() which does not sanitize

Using os.path.basename which only strips directories

Use secure_filename from werkzeug.utils to avoid unsafe file names.

4fill in blank

hard

Fill both blanks to check if the file is allowed and save it.

Flask

if file and '[1]' in file.filename and file.filename.rsplit('.', 1)[1].lower() [2] ALLOWED_EXTENSIONS:
    filename = secure_filename(file.filename)
    file.save(filename)

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A.

Bin

Cnot in

Dstartswith

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'startswith' instead of checking for '.'

Using 'not in' which reverses the logic

Check if filename contains a dot and if the extension is in allowed extensions.

5fill in blank

hard

Fill all three blanks to create a dictionary of filenames and their sizes for allowed files.

Flask

files_info = {file.filename: [1] for file in files if '.' in file.filename and file.filename.rsplit('.', 1)[1].lower() [2] ALLOWED_EXTENSIONS and file [3] None}

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Alen(file.read())

Bin

Cis not

Dfile.size

Attempts:

3 left

💡 Hint

Common Mistakes

Using file.size which is not a standard attribute

Using 'is' instead of 'is not' for None check

We read the file content length, check extension membership, and ensure file is not None.