I'm looking for information on Python bit manipulation, binary manipulation.

It seems that there are no modules for performing Python bit manipulation.

I personally want to be able to:

• Turn "11011000111101..." into bytes, (padded left or right, 0 or 1,) and vice versa.
• Slice ranges of bits
• Rotate bits, addressed by the bit. That is, say: "rotate bits 13-17, wrapping around the edges," or, "rotate bits 13-17, lose bits on the one side, set all new bits to 0."
• Similarly, revert regions of bits, apply logic to regions of bits, etc.,.
• Switch Endianness, with different block sizes.
• Apply operations in block groupings: ex: apply XOR 10101 (5 bits) repeatedly across a field.

The closest thing I've found is [http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/113799 ASPN: bit-field manipulation.]

I imagine that there are many more manipulations people would like to do with bits.

Manipulations

To integer.

   1 >>> print int('00100001', 2)
   2 33

To hex string. Note that you don't need to use x8 bits.

   1 >>> print "0x%x" % int('11111111', 2)
   2 0xff
   3 >>> print "0x%x" % int('0110110110', 2)
   4 0x1b6
   5 >>> print "0x%x" % int('0010101110101100111010101101010111110101010101', 2)
   6 0xaeb3ab57d55

To character. 8 bits max.

   1 >>> chr(int('111011', 2))
   2 ';'
   3 >>> chr(int('1110110', 2))
   4 'v'
   5 >>> chr(int('11101101', 2))
   6 '\xed'

Characters to integers, but not to strings of 1's and 0's.

   1 >>> int('01110101', 2)
   2 117
   3 >>> chr(int('01110101', 2))
   4 'u'
   5 >>> ord('u')
   6 117

Individual bits.

   1 >>> 1 << 0
   2 1
   3 >>> 1 << 1
   4 2
   5 >>> 1 << 2
   6 4
   7 >>> 1 << 3
   8 8
   9 >>> 1 << 4
  10 16
  11 >>> 1 << 5
  12 32
  13 >>> 1 << 6
  14 64
  15 >>> 1 << 7
  16 128

Transformations Summary

Strings to Integers:

• "1011101101": int(str, 2)

• "m": ord(str)

• "0xdecafbad": unknown technique

• "decafbad": unknown technique

Integers to Strings:

• "1011101101": unknown technique

• "m": chr(str)

• "0xdecafbad": hex(val)

• "decafbad": "%x" % val

We are still left without a technique for producing binary strings, and decyphering hex strings.

One approach to decyphering "0xdecafbad" style hex strings, is to use eval:

   1 >>> eval("0xdecafbad ")
   2 3737844653L

However, this could be dangerous, depending on where you're getting your data from.

Research Links

this is the sort of thing we're looking for:

• [http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/113799 ASPN: bit-field manipulation]

related modules:

• [http://www.python.org/doc/current/lib/module-array.html array module] -- (issued with Python)

• [http://www.python.org/doc/current/lib/module-struct.html struct module] -- (issued with Python)

• [http://www.python.org/doc/current/lib/module-binascii.html binascii module] -- (issued with Python)

• [http://pyserial.sourceforge.net/ pySerial module] -- access the serial port

see also: BitwiseOperators