Erle Robotics Learning Python GitBook Free

Exercises:Introduction to Bitwise Operators

Exercise 1

We have the variable a = 0b10111011. Use a bitmask and the value a in order to achieve a result where the third bit from the right of a is turned on. Be sure to print your answer as a bin() string.

Exercise 2

We have the variable a = 0b10111011..Use a bitmask and the value a in order to achieve a result where all of the bits in a are flipped. Be sure to print your answer as a bin() string.

Exercise 3

Define a function called `flip_bit that takes the inputs (number, n). Flip the nth bit (with the ones bit being the first bit) and store it in result. Return the result of calling bin(result).

Solutions

Exercise 1

>>> a = 0b10111011
>>>
>>> bitmask = 0b100
>>> print bin(a | bitmask)
0b10111111

Exercise 2

>>> a = 0b11101110
>>> mask = 0b11111111
>>> result = a^mask
>>> print bin(result)
0b10001
>>>

Exercise 3

>>> def flip_bit(number,n):
...     mask=(0b1<<n-1)
...     return bin(number^mask)
...
>>>
>>> flip_bit(0b1000111,4)
'0b1001111'
>>>

Note:mask=(0b1<<n-1)is going to slide over a number or add zeros to this particular number starting from the right and going left