netpluck 0.9.3

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NetPluck

NetPluck is a tool allows you to remotely extract assets, typically files, from local and remote archives, such as a zip, without fetching or opening the entire archive. NetPluck was specifically designed to be used for very large .zip files that were stored in remote locations such as buckets on Backblaze and CDNs. It is extremely useful if you want to fetch the list of files or extract specific files of very large remote files.

If you intend to fetch and extract all the contents of the archive or your files are very small you don't need this library.

There are three key features of NetPluck:

1. Works very efficiently on large files
2. Can tell you what's in the file without reading the entire thing
3. Extracts specific files without reading the entire thing

NetPluck provides a CLI tool via netpluck and the core python libraries.

Installation

To get access to local and http/https files you can run:

pip install netpluck

If you want access to buckets like backblaze, you should install the optional dependency:

pip install buckethandler

If you don't want to use pip and instead want to install locally via this copy (or want to contribute development) you can run the following after cloning and cd'ing into the repository.

pip install -e .

Formats Supported

1. zip
2. zip64
3. tar

Protocols Supported

1. Local Files
2. Remote Files over HTTP or HTTPS that support range
3. Backblaze B2

Usage

Retrieving the List of Files in the Archive

netpluck --path mini.zip --toc
mini/
mini/empty.txt
mini/lava.png
mini/message.txt
mini/nova.bmp
mini/triangles.png

import netpluck

np = netpluck.NetPluck("mini.zip")
toc = np.get_file_list()
print(toc)
"""
['mini/', 'mini/empty.txt', 'mini/lava.png', 'mini/message.txt', 'mini/nova.bmp', 'mini/triangles.png']
"""

Extracting Files

You can pass regular expressions using --filter to extract files. If you do not specify the --out argument it will default to ./output/

netpluck --path mini.zip --filter="\.*bmp" --out ./output/
[1/1] 100.00% mini/nova.bmp => ./output/mini/nova.bmp

import netpluck

np = netpluck.NetPluck("mini.zip")
files = np.extract_from_filter(r"\.*.bmp","./output/")
"""
[1/1] 100.00% mini/nova.bmp => output\mini\nova.bmp
"""
print(files)
"""
['output\\mini\\nova.bmp']
"""

You can also use the --flatten flag if you want to strip all directories from the resulting output, this will dump all extracted matches into your output folder with no hierarchy.

Getting Statistics

You can enable the --stats flag to see data about bytes and lookups made.

netpluck --path mini.zip --stats --filter="\.*txt" --out ./output/
[1/2]  50.00% empty.txt => ./output/mini/empty.txt
[2/2] 100.00% message.txt => ./output/mini/message.txt

File size: 1.52MB
Cache hits: 7 size: 1.37KB
Uncached reads: 3 size: 64.10KB
Bytes saved: 1.46MB 95.88%

In this instance we read 64kb of the 1556kb file while extracting the two txt files.

Extending

Adding New Protocols and Archives

Protocols in NetPluck are handled by a prefix like: https:// or b2:// to add new ones you must modify the netpluck.py main class and ProtocolType enum. Make sure you modify the _guess_protocol method so it can automatically determine the appropriate one.

Archive types can be extended by adding your own handler to netpluck/virtual_archive and subclassing the VirtualArchive. Be sure to implement all interfaces exposed by VirtualArchive. See the existing zip archive handler for an example. Typically this means you implement __init__ and _read_uncached_range. See netpluck/virtual_file/local.py or netpluck/virtual_file/http.py for a simple example.

You may also need to add a new virtual file type depending on how your data is queried which can be done just like VirtualArchive but with VirtualFile.