Describe and write python program Membership Operators, Identity Operators, Immutable Data Types, Mutable Data Types and Expressions

Sure, let's break down each of these topics:

1. Membership Operators: In Python, membership operators are used to test whether a value or variable is found in a sequence (string, list, tuple, set and dictionary). There are two membership operators as explained below:

   • in: Evaluates to true if it finds a variable in the specified sequence and false otherwise.
   • not in: Evaluates to true if it does not finds a variable in the specified sequence and false otherwise.

   Example:

   x = 'Hello world'
   print('H' in x)  # Outputs: True
   print('hello' not in x)  # Outputs: True
   

2. Identity Operators: Identity operators compare the memory locations of two objects. There are two Identity operators explained below:

   • is: Evaluates to true if the variables on either side of the operator point to the same object and false otherwise.
   • is not: Evaluates to false if the variables on either side of the operator point to the same object and true otherwise.

   Example:

   x = 5
   y = 5
   print(x is y)  # Outputs: True
   print(x is not y)  # Outputs: False
   

3. Immutable Data Types: These are of in-built types like int, float, bool, string, unicode, tuple. In simple words, an immutable object can’t be changed after it is created.

   Example:

   tuple1 = (0, 1, 2, 3)  
   tuple1[0] = 4
   print(tuple1)  # Outputs: TypeError: 'tuple' object does not support item assignment
   

4. Mutable Data Types: These are of type list, dict, set. Custom classes are generally mutable. To simulate immutability in a class, one should override attribute setting and deletion to raise exceptions.

   Example:

   list1 = [1, 2, 3, 4]  
   list1[0] = 9
   print(list1)  # Outputs: [9, 2, 3, 4]
   

5. Expressions: In Python, an expression is a piece of code that produces a value. Expressions consist of values (such as 2) and operators (such as +), and they can always evaluate (that is, reduce) down to a single value.

   Example:

   x = 7
   y = x + 3
   print(y)  # Outputs: 10