Speed comparison of dict implementations

Code

These results were generated with the following code, found in examples/speed.py in the source distribution:

# Simple speed test for various immutable dict implementations

from timeit import timeit

from frozendict import frozendict
from immutabledict import immutabledict
from immutables import Map
from pyrsistent import pmap

from constantdict import constantdict

# Case 1: 1 item
basedict = {1: None}

# Case 2: 1000 items
# basedict = dict.fromkeys(range(1000))

len_dict = len(basedict)

for dict_impl in (dict, constantdict, immutabledict, Map, frozendict, pmap):

    name = dict_impl.__name__  # type: ignore[attr-defined]

    print(name)

    print("  creation\t", timeit(f"{name}({basedict})",
                                 number=10000, globals=globals()))

    try:
        print("  fromkeys\t", timeit(f"{name}.fromkeys(range(len_dict))",
                                     number=10000, globals=globals()))
    except AttributeError:
        print("  fromkeys MISSING")

    try:
        print("  hash\t\t", timeit(f"hash({name}({basedict}))",
                                   number=10000, globals=globals()))
    except (AttributeError, TypeError):
        print("  hash MISSING")

    try:
        print("  hash2\t\t", timeit("for i in range(1000): hash(x)",
                                    setup=f"x={name}({basedict})",
                                    number=10000, globals=globals()))
    except (AttributeError, TypeError):
        print("  hash2 MISSING")

    print("  elem_access\t", timeit(f"{name}({basedict})[1]",
                                    number=10000, globals=globals()))

    print("  list(keys)\t", timeit(f"list({name}({basedict}).keys())",
                                   number=10000, globals=globals()))

Results

Results (total time of 10,0000 executions) for Python 3.11 on a Mac M1: