Skip to main content

A pure-Python memory-efficient packed representation for bit arrays

Project description

This class presents a pure-Python memory efficient packed representation for
bit arrays.

Change introduced in version 1.3.1: Removed the inconsistency in
the internal representation of bit vectors produced by logical bitwise
operations vis-a-vis the bit vectors created by the constructor.
Previously, the logical bitwise operations resulted in bit vectors that
had their bits packed into lists of ints, as opposed to arrays of
unsigned shorts.

Changes introduced in version 1.3: (1) One more constructor mode
included: When initializing a new bit vector with an integer value, you
can now also specify a size for the bit vector. The constructor
zero-pads the bit vector from the left with zeros. (2) The BitVector class
now supports 'if x in y' syntax to test if the bit pattern 'x' is contained
in the bit pattern 'y'. (3) Improved syntax to conform to well-established
Python idioms. (4) What used to be a comment before the beginning of each
method definition is now a docstring.

Changes introduced in version 1.2: (1) one more constructor mode: a bit
vector can now be constructed directly from a bitstring; (2) rich comparison
operators overloaded; (3) minimal length bit vectors constructed from int
values; (4) methods provided for extending a bit vector from the left and from
the right; (5) a unittest based testing framework incorporated in the package;
(6) additional debugging in code and in package setup.

Changes introduced in version 1.1.1: (1) peek feature incorporated in
block reads from disk files; (2) it is now possible to construct zero-sized bit
vectors.

The class supports the following operators/methods:

__getitem__

__setitem__

__len__

__getslice__

__str__

__iter__

__contains__

__int__

__add__

__eq__, __ne__, __lt__, __le__, __gt__, __ge__


'|' for bitwise or

'&' for bitwise and

'^' for bitwise xor

'~' for bitwise inversion

'<<' for circular shift to the left

'>>' for circular shift to the right

'+' for concatenation

intValue(), __int__ for returning the integer value

divide_into_two

permute

unpermute

pad_from_left

pad_from_right

read_bits_from_file

write_to_file

read_bits_from_fileobject

write_bits_to_fileobject

Project details


Supported by

AWS AWS Cloud computing Datadog Datadog Monitoring Facebook / Instagram Facebook / Instagram PSF Sponsor Fastly Fastly CDN Google Google Object Storage and Download Analytics Huawei Huawei PSF Sponsor Microsoft Microsoft PSF Sponsor NVIDIA NVIDIA PSF Sponsor Pingdom Pingdom Monitoring Salesforce Salesforce PSF Sponsor Sentry Sentry Error logging StatusPage StatusPage Status page