Python PCEP Logic Bit Operations
- 1. Module 2 Data Collections – Lists, Tuples, and Dictionaries Logic and bit operations
- 2. Module 2 Logic and bit operations Computer logic Argument A Argument B A and B False False False False True False True False False True True True and not Argument not Argument False True True False or Argument A Argument B A or B False False False False True True True False True True True True
- 3. Module 2 Logic and bit operations Bitwise operators • & (ampersand) - bitwise conjunction • | (bar) - bitwise disjunction • ~ (tilde) - bitwise negation • ^ (caret) - bitwise exclusive or (xor) Argument A Argument B A & B A | B A ^ B 0 0 0 0 0 0 1 0 1 1 1 0 0 1 1 1 1 1 1 0 Bitwise operations (&, |, and ^) Bitwise operations (~) Argument ~ Argument 0 1 1 0
- 4. Module 2 Logic and bit operations Logical vs. bit operations i = 15 j = 22 i: 00000000000000000000000000001111 j: 00000000000000000000000000010110 log = i and j log: True bit = i & j i 00000000000000000000000000001111 j 00000000000000000000000000010110 bit = i & j 00000000000000000000000000000110
- 5. Module 2 Logic and bit operations How do we deal with single bits flag_register = 0x1234 flag_register = 0000000000000000000000000000x000 Check the state of your bit • x & 1 = x • x & 0 = 0 Reset your bit • flag_register = flag_register & ~the_mask • flag_register &= ~the_mask Set your bit • x | 1 = 1 • x | 0 = x Negate your bit • x ^ 1 = ~x • x ^ 0 = x
- 6. Module 2 Logic and bit operations Binary left shift & binary right shift value << bits value >> bits var = 17 var_right = var >> 1 var_left = var << 2 print(var, var_left, var_right) 17 68 8 Priority Operator 1 ˜ , + , - unary 2 ** 3 * , / , // , % 4 + , - binary 5 << , >> 6 <, <= , > , >= 7 == , != 8 & 9 | 10 =, +=, -=, *=, /=, %=, &=, ˆ=, |=, >>=, <<=
- 7. Module 2 Logic and bit operations Key takeaways Logical operators: • and, or, not To use bitwise operators to manipulate single bits of data: • x = 15, which is 0000 1111 in binary • y = 16, which is 0001 0000 in binary • & and, | or, ˜ not, ˆ xor, >> right shift, << left shift