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P. 162

-=       Subtraction and     The operator subtracts the value on the RHS  >>> b -= 2
                      assignment          of the operator  from the value on the LHS   >>> b
                                          of the operator and assigns the result to the       3
                                          operand on the  LHS of the  operator.  Note   >>> c -= 8 // 4
                                          that the expression on the RHS is evaluated   >>> c
                                          before applying  -=                           -4

             -=       Multiplication  and  The operator multiplies the value on the LHS  >>> b *= 3
                      assignment          of the operator by the value on the RHS of  >>> b
                                          the operator and  assigns  the  result to the      15
                                          operand  on  the LHS  of  the operator.  Note  >>> c *= 5 + 3
                                          that the expression on the RHS is evaluated  >>> c
                                          before applying *=                            -16
             /=       Division and        The operator divides the value on the LHS of  >>> a /= 4
                      assignment          the operator by the value on the RHS of the  >>> a
                                          operator and assigns the quotient (float) to      2.5
                                          the operand on the LHS of the operator. Note  >>> a /= 2 + 3
                                          that the expression on the RHS is evaluated  >>> a
                                          before applying /=                            2.0
             %=       Modulus and         The operator divides the value on the LHS of  >>> a %= 3
                      assignment          the operator by the value on the RHS of the   >>> a
                                          operator and assigns  the remainder to the       1
                                          operand on its left. Note that the expression   >>> a %= 2 + 4
                                                                                    >>> a
                                          on the RHS is evaluated before applying %=
                                                                                        4
             //=      Integer division and  The operator divides the value on the LHS of  >>> a //= 3
                      assignment          the operator by the value on the RHS of the   >>> a
                                          operator  and  assigns  the  quotient  (int)  to       3
                                          the operand on the LHS of the operator. Note   >>> c //= 2
                                          that the expression on the RHS is evaluated   >>> c
                                                                                        -1
                                          before applying //=
                                                                                    >>> a //= 1 + 3
                                                                                    >>> a
                                                                                        2
             **=      Exponentiation and  The operator computes  (operand on the LHS  >>> b **= 3
                      assignment          of **=)** (operand on the RHS of **=)  and   >>> b
                                          assigns the result to the operand on the LHS       125
                                          of the operator. Note that the expression on   >>> c **= 2 * 3
                                                                                    >>> c
                                          the RHS is evaluated before applying **=.
                                                                                        64
        7.5.4 Logical Operators
        A logical value is True or False. The logical operators yield True or False, depending upon the value of logical
        operands on either side. A value other than 0 and None evaluates to True while zero evaluates to False. Therefore,
        1, "bb",  and -1 are interpreted as  True but 0  and None are interpreted as False. There are three logical
        operators: and, or, and not. Note that all three operators are keywords and are used in lowercase only. Further,
        in an expression, the precedence of the operators in decreasing order is: not, and, or. These operators may be
        used to express relationships between relational expressions. For detailed description of these operators, see Table
        7.4: Logical Operators.


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