In Perl I can create a large bit vector as follows:
vec($bitmap,10000000,1) = 0; # this will create a bit string of all zeros
To set bits I may using commands like:
vec($bitmap,1000, 1) = 1 # turn on bit 1000
vec($bitmap,10000, 1) = 1 # turn on bit 10000
vec($bitmap,1000000, 1) = 1 # turn on bit 10000000
which would set three bits in the string $bitmap - Note: in perl I don't
even have to declare $bitmap until I use it in the vec command.
Anyway there is a very cool perl command which return the number of bits set
in a large bitmap string instantly.
The command is:
$setbits = unpack("%32b*", $bitmap);
Which in this case would store the number 3 in $setbits
Is there an equivalent command in python that would immediately provide the
number of set bits in a large bit vector/string
I know I could loop through but when you have 10,000,000 or 100,000,000
bits, the looping takes quite a while the perl unpack is instant.
Thanks for any help you could provide
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