Code Completion 4 Challenges

Complete the Python TAR archive code

Practise creating TAR members, reading member bytes, and extracting with an explicit data filter.

Intermediate ~12 min read

Add the existing source file to the open TAR archive under the portable member name reports/notes.txt.

python Your answer

from pathlib import Path
from tempfile import TemporaryDirectory
import tarfile

with TemporaryDirectory() as folder:
    root = Path(folder)
    source = root / "notes.txt"
    source.write_text("ready", encoding="utf-8")
    archive_path = root / "notes.tar"
    with tarfile.open(archive_path, "w") as archive:
        
    with tarfile.open(archive_path) as archive:
        assert archive.getnames() == ["reports/notes.txt"]
    print("portable member name stored")

Press Ctrl⌘Enter to check your answer

Create and add a TarInfo member containing the supplied bytes without making a source file.

python Your answer

import io
import tarfile
from pathlib import Path
from tempfile import TemporaryDirectory

with TemporaryDirectory() as folder:
    archive_path = Path(folder) / "data.tar"
    payload = b"ready"
    member = tarfile.TarInfo("status.txt")
    member.size = len(payload)
    with tarfile.open(archive_path, "w") as archive:
        
    with tarfile.open(archive_path) as archive:
        with archive.extractfile("status.txt") as stream:
            assert stream.read() == payload
    print("member stored")

Press Ctrl⌘Enter to check your answer

Read a member as a binary stream, then decode its UTF-8 content.

python Your answer

from pathlib import Path
from tempfile import TemporaryDirectory
import tarfile

with TemporaryDirectory() as folder:
    root = Path(folder)
    source = root / "hello.txt"
    source.write_text("Hello", encoding="utf-8")
    archive_path = root / "hello.tar"
    with tarfile.open(archive_path, "w") as archive:
        archive.add(source, arcname="hello.txt")
    with tarfile.open(archive_path) as archive:
        with archive.extractfile("hello.txt") as stream:
            message = 
    assert message == "Hello"
    print(message)

Press Ctrl⌘Enter to check your answer

Extract the known member to the temporary destination using the standard data filter.

python Your answer

from pathlib import Path
from tempfile import TemporaryDirectory
import tarfile

with TemporaryDirectory() as folder:
    root = Path(folder)
    source = root / "hello.txt"
    source.write_text("Hello", encoding="utf-8")
    archive_path = root / "hello.tar"
    with tarfile.open(archive_path, "w") as archive:
        archive.add(source, arcname="hello.txt")
    destination = root / "out"
    destination.mkdir()
    with tarfile.open(archive_path) as archive:
        
    assert (destination / "hello.txt").read_text(encoding="utf-8") == "Hello"
    print("controlled extraction complete")

Press Ctrl⌘Enter to check your answer