Library for working with file-likes as piped streams
Project description
fPipe
python framework for data manipulation and metadata extraction built around the python file-like api.
Disclaimer: framework is currently in Alpha, production use discouraged
Installing
Designed for python 3.7, for S3 support you need boto3
brew install python3
pip3 install fpipe
# Optional
pip3 install boto3
Getting started
Example that reads a stream, calculates some file info, writes file to disk and prints the original stream to stdout
#!/usr/bin/env python3
import io
from fpipe import FileStream
from fpipe.calculators import SizeCalculated, MD5CheckSum
from fpipe.file import Path
from fpipe.generators import FileInfoGenerator, LocalFileGenerator
example_streams = (
FileStream(
io.BytesIO(
bytes(f'{name}', encoding='utf-8') * 2 ** 6
),
meta=[Path(f'{name}.file')]
)
for name in ('x', 'y', 'z')
)
gen = FileInfoGenerator(example_streams, [SizeCalculated, MD5CheckSum])
for f in LocalFileGenerator(gen, pass_through=True, pathname_resolver=lambda x: x.meta(Path).value):
print(f"Name: {f.meta(Path)}")
while True:
b = f.file.read(2)
print(b.decode('utf-8'), end='')
if not b:
break
print(f"\nChecksum: {f.meta(MD5CheckSum).value}\n")
See unittests for more examples
Run tests and verify pypi compatibility
To run tests install tox and twine with pip, go to project root and run tox
# python3 -m venv .venv
# Activate virtualenv
source .venv/bin/activate
# Run tests
tox
# Build distribution
python setup.py sdist bdist_wheel
# Validate distribution
twine check dist/*
Rationale
NOTE: wip
Unix pipes or chained python generators are ideal when the pipeline does not split and does not require metadata from previous steps.
Working around these challenges may lead to unnecessary complication and caching.
This framework's main intentions are to provide general solutions to the aforementioned challenges through a minimalistic and intuitive API.
Design
NOTE: wip
The whole framework is built around 2 main concepts:
- class File
- Base class for files
- class FileGenerator
- Initialized with an iterable of Files and yields a different File
Files have 3 different type:
- class FilePointer(File): A pointer to a file that could be used to produce a FileStream
- class FileStream(File): File that produces a data stream
- class FileSeekableStream(FileStream) File that produces a seekable stream
In addition we have class FileMeta which provides meta-data often needed by FileGenerators to be able to generate files.
Built With
- travis
- tox
Contributing
Bug-reports and pull requests on github
Versioning
Any version change could break the public API (until 1.0.0 release)
License
This project is licensed under the MIT License - see the LICENSE.txt file for details
Project details
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