bitwise XOR of hex numbers in python

Question

how can we XOR hex numbers in python eg  I want to xor  ABCD  to  12EF   answer should be B922   i used below code but it is returning garbage value  def strxor a  b         xor two strings of different lengths  if len a   gt  len b       return    join    s     ord x    ord y   for  x  y  in zip a  len b    b    else      return    join    s     ord x    ord y   for  x  y  in zip a  b  len a       key   12ef  m1  abcd  print  strxor key m1

User · Answer

If the two hex strings are the same length and you want a hex string output then you might try this    def hexxor a  b        xor two hex strings of the same length     return    join    x     int x 16    int y 16   for  x  y  in zip a  b

User · Answer

If the strings are the same length  then I would go for   x       of the built-in xor        Examples -    gt  gt  gt a    290b6e3a   gt  gt  gt b    d6f491c5   gt  gt  gt   x     int a 16  int b 16    ffffffff   gt  gt  gt c    abcd   gt  gt  gt d    12ef   gt  gt  gt   x     int a 16  int b 16    b922    If the strings are not the same length  truncate the longer string to the length of the shorter using a slice longer   longer  len shorter

User · Answer

here s a better function  def strxor a  b         xor two strings of different lengths     if len a   gt  len b           return    join  chr ord x    ord y   for  x  y  in zip a  len b    b        else          return    join  chr ord x    ord y   for  x  y  in zip a  b  len a

User · Answer

For performance purpose  here s a little code to benchmark these two alternatives      bin python  def hexxorA a  b       if len a   gt  len b           return    join    x     int x 16    int y 16   for  x  y  in zip a  len b    b        else          return    join    x     int x 16    int y 16   for  x  y  in zip a  b  len a       def hexxorB a  b       if len a   gt  len b           return   x     int a  len b   16  int b 16       else          return   x     int a 16  int b  len a   16    def testA        strstr   hexxorA  b4affa21cbb744fa9d6e055a09b562b87205fe73cd502ee5b8677fcd17ad19fce0e0bba05b1315e03575fe2a783556063f07dcd0b9d15188cee8dd99660ee751    5450ce618aae4547cadc4e42e7ed99438b2628ff15d47b20c5e968f086087d49ec04d6a1b175701a5e3f80c8831e6c627077f290c723f585af02e4c16122b7e2       if not int strstr  16     int  e0ff3440411901bd57b24b18ee58fbfbf923d68cd88455c57d8e173d91a564b50ce46d01ea6665fa6b4a7ee2fb2b3a644f702e407ef2a40d61ea3958072c50b3   16           raise KeyError     return strstr  def testB        strstr   hexxorB  b4affa21cbb744fa9d6e055a09b562b87205fe73cd502ee5b8677fcd17ad19fce0e0bba05b1315e03575fe2a783556063f07dcd0b9d15188cee8dd99660ee751    5450ce618aae4547cadc4e42e7ed99438b2628ff15d47b20c5e968f086087d49ec04d6a1b175701a5e3f80c8831e6c627077f290c723f585af02e4c16122b7e2       if not int strstr  16     int  e0ff3440411901bd57b24b18ee58fbfbf923d68cd88455c57d8e173d91a564b50ce46d01ea6665fa6b4a7ee2fb2b3a644f702e407ef2a40d61ea3958072c50b3   16           raise KeyError     return strstr  if   name         main         import timeit     print  Time-it 100k iterations         print   thexxorA     end         print timeit timeit  testA     setup  from   main   import testA   number 100000   end  s n       print   thexxorB     end         print timeit timeit  testB     setup  from   main   import testB   number 100000   end  s n     Here are the results    Time-it 100k iterations       hexxorA  8 139988073991844s     hexxorB  0 240523161992314s   Seems like   x     int a 16  int b 16   is faster then the zip version

User · Answer

Whoa  You re really over-complicating it by a very long distance  Try    gt  gt  gt  print hex 0x12ef   0xabcd  0xb922   You seem to be ignoring these handy facts  at least    Python has native support for hexadecimal integer literals  with the 0x prefix   Hexadecimal  is just a presentation detail  the arithmetic is done in binary  and then the result is printed as hex  There is no connection between the format of the inputs  the hexadecimal literals  and the output  there is no such thing as a  hexadecimal number  in a Python variable  The hex   function can be used to convert any number into a hexadecimal string for display    If you already have the numbers as strings  you can use the int   function to convert to numbers  by providing the expected base  16 for hexadecimal numbers     gt  gt  gt  print int  12ef   16  4874   So you can do two conversions  perform the XOR  and then convert back to hex    gt  gt  gt  print hex int  12ef   16    int  abcd   16   0xb922

[python] bitwise XOR of hex numbers in python

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