From: Back9 on 17 Jun 2010 15:51 Hi, I have one byte data and want to know each bit info, I mean how I can know each bit is set or not? TIA From: Tim Lesher on 17 Jun 2010 16:06 On Jun 17, 3:51 pm, Back9 wrote:> Hi, > > I have one byte data and want to know each bit info, > I mean how I can know each bit is set or not? You want the bitwise-and operator, &. For example, to check the least significant bit, bitwise-and with 1: >>> 3 & 1 1>>> 2 & 1 0 From: Laurent Verweijen on 17 Jun 2010 16:08 Op donderdag 17-06-2010 om 12:51 uur [tijdzone -0700], schreef Back9: > Hi, > > I have one byte data and want to know each bit info, > I mean how I can know each bit is set or not? > > TIA def bitset(x, n): """Return whether nth bit of x was set""" return bool(x & (1 << n)) From: Irmen de Jong on 17 Jun 2010 16:10 On 17-6-2010 21:51, Back9 wrote:> Hi, > > I have one byte data and want to know each bit info, > I mean how I can know each bit is set or not? > > TIA Use bitwise and, for instance, to see if the third bit is set: byte = 0b11111111 if byte & 0b00000100: print "bit is set" -irmen From: Stephen Hansen on 17 Jun 2010 16:14 On 6/17/10 12:51 PM, Back9 wrote:> I have one byte data and want to know each bit info, > I mean how I can know each bit is set or not? >>> BIT_1 = 1 << 0 >>> BIT_2 = 1 << 1 >>> BIT_3 = 1 << 2 >>> BIT_4 = 1 << 3 >>> BIT_5 = 1 << 4 >>> BIT_6 = 1 << 5 >>> BIT_7 = 1 << 6 >>> BIT_8 = 1 << 7 >>> byte = 67 >>> if byte & BIT_1: ... print "Bit 1 is set!" ... else: ... print "Bit 1 is not set!" Bit 1 is set!>>> if not byte & BIT_6: ... byte = byte | BIT_6 ... print "Bit 6 wasn't set, BUT NOW IS." Bit 6 wasn't set, BUT NOW IS.>>> byte 99 (I added 'how to set a specific bit' just cuz) Basically, those BIT_X lines are creating numbers which have *only* the specified bit set. Then you do "byte & BIT_X", and that will return 0 if the byte doesn't have the specified bit in it. You can then set the bit with "byte | BIT_X", and unset the bit with "byte ^ BIT_X". -- Stephen Hansen ... Also: Ixokai ... Mail: me+list/python (AT) ixokai (DOT) io ... Blog: http://meh.ixokai.io/