A python implementation of the bloom filter used by Ethereum.
This library and repository was previously located at https://github.com/pipermerriam/ethereum-bloom. It was transferred to the Ethereum foundation github in November 2017 and renamed to
eth-bloom
. The PyPi package was also renamed fromethereum-bloom
to `eth-bloom.
Read more in the documentation below. View the change log.
For more information on what Ethereum Bloom Filters are see here.
python -m pip install eth-bloom
The BloomFilter
object
>>> from eth_bloom import BloomFilter
>>> b = BloomFilter()
>>> b'a value' in b # check whether a value is present
False
>>> b.add(b'a value') # add a single value
>>> b'a value' in b
True
>>> int(b) # cast to an integer
3458628712844765018311492773359360516229024449585949240367644166080576879632652362184119765613545163153674691520749911733485693171622325900647078772681584616740134230153806267998022370194756399579977294154062696916779055028045657302214591620589415314367270329881298073237757853875497241510733954508399863880080986777555986663988492288946856978031023631618215522505971170427986911575695114157059398791122395379400594948096
>>> bin(b) # cast to a binary string
'0b100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000'
You can also add an iterable of items to a bloom filter.
>>> b = BloomFilter()
>>> b'value-a' in b
False
>>> b'value-b' in b
False
>>> b.extend([b'value-a', b'value-b'])
>>> b'value-a' in b
True
>>> b'value-b' in b
True
You can initialize a bloom filter from an iterable of byte strings.
>>> b = BloomFilter.from_iterable([b'value-a', b'value-b']) # initialize from an iterable of values.
>>> b'value-a' in b
True
>>> b'value-b' in b
True
You can initialize a bloom filter from the integer representation of the bloom bits.
>>> b = BloomFilter(3458628712844765018311492773359360516229024449585949240367644166080576879632652362184119765613545163153674691520749911733485693171622325900647078772681584616740134230153806267998022370194756399579977294154062696916779055028045657302214591620589415314367270329881298073237757853875497241510733954508399863880080986777555986663988492288946856978031023631618215522505971170427986911575695114157059398791122395379400594948096)
>>> b'a value' in b
True
You can also merge bloom filters
>>> from eth_bloom import BloomFilter
>>> b1 = BloomFilter()
>>> b2 = BloomFilter()
>>> b1.add(b'a')
>>> b1.add(b'common')
>>> b2.add(b'b')
>>> b2.add(b'common')
>>> b'a' in b1
True
>>> b'b' in b1
False
>>> b'common' in b1
True
>>> b'a' in b2
False
>>> b'b' in b2
True
>>> b'common' in b2
True
>>> b3 = b1 + b2 # using addition
>>> b'a' in b3
True
>>> b'b' in b3
True
>>> b'common' in b3
True
>>> b4 = b1 | b2 # or using bitwise or
>>> b'a' in b4
True
>>> b'b' in b4
True
>>> b'common' in b4
True
>>> b1 |= b2 # or using in-place operations (works with += too)
>>> b'a' in b1
True
>>> b'b' in b1
True
>>> b'common' in b1
True
If you would like to hack on eth-bloom, please check out the Snake Charmers Tactical Manual for information on how we do:
- Testing
- Pull Requests
- Documentation
We use pre-commit to maintain consistent code style. Once
installed, it will run automatically with every commit. You can also run it manually
with make lint
. If you need to make a commit that skips the pre-commit
checks, you
can do so with git commit --no-verify
.
You can set up your dev environment with:
git clone [email protected]:ethereum/eth-bloom.git
cd eth-bloom
virtualenv -p python3 venv
. venv/bin/activate
python -m pip install -e ".[dev]"
pre-commit install
To release a new version:
make release bump=$$VERSION_PART_TO_BUMP$$
The version format for this repo is {major}.{minor}.{patch}
for stable, and
{major}.{minor}.{patch}-{stage}.{devnum}
for unstable (stage
can be alpha or beta).
To issue the next version in line, specify which part to bump,
like make release bump=minor
or make release bump=devnum
. This is typically done from the
main branch, except when releasing a beta (in which case the beta is released from main,
and the previous stable branch is released from said branch).
If you are in a beta version, make release bump=stage
will switch to a stable.
To issue an unstable version when the current version is stable, specify the
new version explicitly, like make release bump="--new-version 4.0.0-alpha.1 devnum"