ctools 0.0.3

A collection of useful functions for python implement in C.

A collection of useful functions for python implement in C.

Installation

Install and update using pip (python3 only):

pip install -U ctools

API

• A consistent hash implement. See paper at jump_consistent_hash.

jump_consistent_hash(key: int, num_buckets: int) -> int:
    """Generate a number in the range [0, num_buckets).

    This function uses C bindings for speed.

    :param key: The key to hash.
    :type key: int
    :param num_buckets: Number of buckets to use.
    :type num_buckets: int
    :return: hash number
    :rtype: int
    """

• A normal hash function for str with consistent value.

strhash(s: str) -> int:
    """
    hash str with consistent value.

    This function uses C bindings for speed.

    :param s: The string to hash.
    :type s: string
    :return: hash number
    :rtype: int
    """

• Transfer integer like 20170101 (Java style) to python datetime object.

int8_to_datetime(date_integer: int) -> datetime.datetime:
    """
    Convert int like 20180101 to datetime.datetime(2018, 1, 1)).

    This function uses C bindings for speed.

    :param date_integer: The string to hash.
    :type date_integer: int
    :return: parsed datetime
    :rtype: datetime.datetime
    """

Benchmark

$ make install && make benchmark
int8_to_datetime(20170101),         62.393 ns ± 2.328 ns each (10 runs, 1,000,000 loops)
jump_consistent_hash(65535, 1024),  151.440 ns ± 8.359 ns each (10 runs, 1,000,000 loops)
strhash('zxgfhyxjhjtepqoikns'),     120.241 ns ± 6.072 ns each (10 runs, 1,000,000 loops)

How To Test

$ make install && make test

More

$ make help