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Python bindings for the Rust `fst` crate, providing sets and maps backed by finite state transducers.

Project description

Python bindings for burntsushi’s fst crate (rustdocs)
for FST-backed sets and maps.
For reasons why you might want to consider using it, see BurntSushi’s great


  • Work with larger-than-memory sets
  • Perform fuzzy search using Levenshtein automata


  • You will need:
    • Python >= 3.3, Python or PyPy >= 2.7 with development headers installed
    • Rust nightly (install via rustup)
  • Clone the repository. Installation with pip install git+... does not work currently
  • Run rustup override add nightly to add an override for rustup to use the nightly channel for the repository
  • Run python bdist_wheel to generate a wheel
  • Install the wheel with pip install dist/rust_fst-0.1-py3-none-any.whl


The package exposes almost all functionality of the fst crate, except for:

  • Combining the results of slicing, search and search_re with set operations
  • Using raw transducers


from rust_fst import Map, Set

# Building a set in memory
keys = ["fa", "fo", "fob", "focus", "foo", "food", "foul"]
s = Set.from_iter(keys)

# Fuzzy searches on the set
matches = list("foo", max_dist=1))
assert matches == ["fo", "fob", "foo", "food"]

# Searching with a regular expression
matches = list(s.search_re(r'f\w{2}'))
assert matches == ["fob", "foo"]

# Store map on disk, requiring only constant memory for querying
items = [("bruce", 1), ("clarence", 2), ("stevie", 3)]
m = Map.from_iter(items, path="/tmp/map.fst")

# Find all items whose key is greater or equal (in lexicographical sense) to
# 'clarence'
matches = dict(m['clarence':])
assert matches == {'clarence': 2, 'stevie': 3}


Head over to for the API documentation.

If you want to know more about performance characteristics, memory usage
and about the implementation details, please head over to the

Project details

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Filename, size & hash SHA256 hash help File type Python version Upload date
rust_fst-0.1.2-py2.py3-none-macosx_10_9_x86_64.whl (858.1 kB) Copy SHA256 hash SHA256 Wheel py2.py3 May 26, 2016
rust_fst-0.1.2-py2.py3-none-manylinux1_x86_64.whl (1.0 MB) Copy SHA256 hash SHA256 Wheel py2.py3 May 26, 2016
rust_fst-0.1.2-py2.py3-none-win32.whl (1.2 MB) Copy SHA256 hash SHA256 Wheel py2.py3 May 26, 2016
rust_fst-0.1.2-py2.py3-none-win_amd64.whl (1.3 MB) Copy SHA256 hash SHA256 Wheel py2.py3 May 26, 2016
rust-fst-0.1.2.tar.gz (8.3 kB) Copy SHA256 hash SHA256 Source None May 26, 2016

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