constantdict 2024.2

An immutable dict class.

constantdict

An immutable dictionary class for Python, implemented as a thin layer around Python's builtin dict class. It is often faster than other immutable dictionary implementations.

Usage

Install this package with:

$ pip install constantdict

Usage example:

from constantdict import constantdict

cd = constantdict({1: 2})

# constantdicts compare equal to dicts with the same items
assert cd == {1: 2}

# constantdicts are hashable, and their hashes are cached
print(hash(cd), cd)

# Attempting to modify the constantdict raises an AttributeError
try:
    # Similar for pop(), popitem(), clear(), __ior__(), del, and setdefault()
    cd[4] = 12
except AttributeError:
    pass

Please also see the documentation, as well as the examples in the examples/ directory.

References

Other packages

• immutabledict
• immutables
• pyrsistent
• frozendict (old)
• frozendict (new)

PEPs

• PEP 416
• PEP 603

License

MIT License.