Oct 28, 2014 · you could easily change it to (not 'a') in ['b', False] which would give you the answer you apparently expect (since parens always denote higher precedence)

Python’s not operator allows you to invert the truth value of Boolean expressions and objects. You can use this operator in Boolean contexts, such as if statements and while loops. It also works in non-Boolean contexts, which allows you to invert the truth value of your variables.

Apr 7, 2025 · The not keyword in Python is a logical operator used to obtain the negation or opposite Boolean value of an operand. It is a unary operator, meaning it takes only one operand and returns its complementary Boolean value.

In this tutorial, you'll learn how to check if a given value is present or absent in a collection of values using Python's in and not in operators, respectively.

Dec 22, 2020 · If you look at De Morgan's laws there's a simple transformation available; when you distribute the not into the parentheses, you flip from and to or (and vice-versa), so not (A and B) is equivalent to not A or not B; if you make a truth table for that, you'll find they match perfectly.

Nov 6, 2015 · Technically, it's very slightly faster to use the latter, e.g. not (A and B), as the interpreter evaluates fewer logical statements, but it's trivial. Use the logical structure that allows you to state the condition as clearly as possible, on a case-by-case basis.

The Python "not" operator is an essential tool for logical negation in conditions, loops, and expressions. Learning to properly use the "not" Boolean operator lets you write cleaner, more …

Oct 19, 2022 · not is a unary operator which means it takes only one input value. It can be used with any boolean expression or Python object.

What is a Logical Operator? A logical operator is one or two symbols or a keyword that tells the computer how to combine conditional statements. The result of using a logical operator is a boolean value (true or false). See this page for an overview of other types of operators. The most common logical operators are: && (Logical AND) || (Logical OR) ! (Logical NOT) In the example below, we use ...

In Python, the not keyword is a logical operator that inverts the truth value of the expression returning True or False. It’s also used in negated membership tests with the not in operator and negated identity checks with the is not the operator.