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.
Version 2.0.1 removes many typos and other errors in the documentation page. The implementation code remains the same as in Version 2.0
Version 2.0 provides much additional functionality that was requested by folks in the data mining community. The class now includes faster methods for counting bits, for finding the position of the next set bit, for calculating the rank of a bit, for determining the Jaccard and Hamming distances, etc. Also included in the new version are methods that should prove useful to folks who play with cryptography algorithms. There is now a method that calculates the greatest common divisor of two bit vectors and a method that finds the multiplicative inverse of a bit vector vis-a-vis a given modulus.
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
slice assignment
reset
setValue
count_bits
count_bit_sparse
jaccard_similarity
jaccard_distance
hamming_distance
next_set_bit
rank_of_bit_set_at_index
isPowerOf2
isPowerOf2_sparse
reverse
gcd
multiplicative_inverse
