How can I check if a string contains only ASCII alphanumeric characters and spaces in Python?
Rashid D

In Python, class attributes and instance attributes are both ways to store and access data associated with a class. However, they have distinct behaviors and purposes. Here's a long-form explanation of the differences between class attributes and instance attributes: Class Attributes: 1. Definition: - Class attributes are variables defined within a class but outside of any methods. - They are shared among all instances of the class and belong to the class itself. - Class attributes are defined directly in the class body, typically at the top, and are accessed using the class name or any instance of the class. 2. Access and Modification: - Class attributes can be accessed and modified by any instance of the class or by the class itself. - When accessing a class attribute, Python first checks if the attribute exists in the instance. If not found, it looks for the attribute in the class. - Modifying a class attribute affects all instances of the class, as they share the same attribute value. 3. Example:

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   class MyClass:
  class_attribute = "Class Value"
   
   instance1 = MyClass()
   instance2 = MyClass()
   
   print(instance1.class_attribute) # Output: Class Value
   print(instance2.class_attribute) # Output: Class Value
   
   MyClass.class_attribute = "New Value"
   
   print(instance1.class_attribute) # Output: New Value
   print(instance2.class_attribute) # Output: New Value

Instance Attributes: 1. Definition: - Instance attributes are variables specific to each instance of a class. - They are defined and accessed within methods or the__init__ method (constructor) of the class. - Each instance of the class has its own set of instance attributes, which are separate from other instances. 2. Access and Modification: - Instance attributes can be accessed and modified only within the scope of the specific instance where they are defined. - When accessing an instance attribute, Python first checks if the attribute exists in the instance. If not found, it does not search in the class. - Modifying an instance attribute affects only the specific instance where the modification is made and does not impact other instances or the class. 3. Example:

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   class MyClass:
  def __init__(self):
 self.instance_attribute = "Instance Value"
   
   instance1 = MyClass()
   instance2 = MyClass()
   
   print(instance1.instance_attribute) # Output: Instance Value
   print(instance2.instance_attribute) # Output: Instance Value
   
   instance1.instance_attribute = "New Value"
   
   print(instance1.instance_attribute) # Output: New Value
   print(instance2.instance_attribute) # Output: Instance Value

To summarize: - Class attributes are shared among all instances of a class and belong to the class itself. - They are defined outside of any methods within the class body and can be accessed using the class name or any instance of the class. - Modifying a class attribute affects all instances. - Instance attributes are specific to each instance of a class and are defined and accessed within methods or the__init__ method. - Each instance has its own set of instance attributes, separate from other instances. - Modifying an instance attribute affects only the specific instance. Choose between class attributes and instance attributes based on whether the data should be shared among all instances or specific to each instance.

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