and, or, not, in, is In Python

Python and Keyword

This a logical operator in Python. “and” Return the first false value. If not found return last. The truth table for “and” is depicted below. 

3 and 0 return 0 

3 and 10 return 10 

10 or 20 or 30 or 10 or 70 returns 10 

The above statements might be a bit confusing to a programmer coming from a language like C where the logical operators always return boolean values(0 or 1). The following lines are straight from the Python docs explaining this:

The expression x and y first evaluates x; if x is false, its value is returned; otherwise, y is evaluated and the resulting value is returned.

The expression x or y first evaluates x; if x is true, its value is returned; otherwise, y is evaluated and the resulting value is returned.

Note that neither and nor restrict the value and type they return to False and True, but rather return the last evaluated argument. This is sometimes useful, e.g., if s is a string that should be replaced by a default value if it is empty, the expression s or ‘foo’ yields the desired value. Because not has to create a new value, it returns a boolean value regardless of the type of its argument (for example, not ‘foo’ produces False rather than ”.)

Python or Keyword

This a logical operator in Python. “or” Return the first True value. if not found return last. The truth table for “or” is depicted below. 
 

3 or 0 returns 3 
3 or 10 returns 3 
0 or 0 or 3 or 10 or 0 returns 3 

• not: This logical operator inverts the truth value. The truth table for “not” is depicted below. 
• in: This keyword is used to check if a container contains a value. This keyword is also used to loop through the container.
• is: This keyword is used to test object identity, i.e to check if both the objects take the same memory location or not. 

and, or, not, is and in keyword implementation in Python

The provided code demonstrates various Python operations:

1. Logical Operations:
   • 'or' returns ‘True' when at least one operand is ‘True'.
   • 'and' returns ‘True' only when both operands are ‘True'.
   • 'not' negates the operand.
2. Python “in” Keyword:
   • It checks if ‘s’ is in the string ‘w3wiki’ and prints accordingly.
   • It loops through the string’s characters.
3. Python “is” Keyword:
   • It checks if two empty strings (‘ ‘) are identical (returns ‘True').
   • It checks if two empty dictionaries ({}) are identical (returns ‘False').

Output

True
False
False
s is part of w3wiki
g e e k s f o r g e e k s 
True
False

Every language contains words and a set of rules that would make a sentence meaningful. Similarly, in Python programming language, there are a set of predefined words, called Keywords which along with Identifiers will form meaningful sentences when used together. Python keywords cannot be used as the names of variables, functions, and classes.

In this article, we will learn about Python keywords and how to use them to perform some tasks.