What is reflection in the context of Python?

The ability of a program to explore and modify its own structure and behavior at runtime. Allows working with objects, types, functions, and modules whose names or structures are unknown prior to code execution.

Main features:

Getting information about type/object:
- type() - get the type of an object.
- isinstance() - check if an object is an instance of a class or subclass.
- issubclass() - check if one class is a subclass of another.
Access to attributes:
- getattr(obj, name[, default]) - get the value of an attribute.
- setattr(obj, name, value) - set the value of an attribute.
- hasattr(obj, name) - check if an attribute exists.
- delattr(obj, name) - delete an attribute.
Access to documentation:
- help() - interactive help.
- __doc__ - access to the object's docstring.
Executing code:
- eval(expression[, globals[, locals]]) - execute a string as a Python expression.
- exec(object[, globals[, locals]]) - execute a string or code object.
Exploring namespace:
- dir([object]) - list of names in the current namespace or attributes of an object.
- globals() - dictionary of global variables in the current module.
- locals() - dictionary of local variables in the current function or module.

Examples of usage:

class MyClass:
    def __init__(self, value):
        self.value = value

    def my_method(self):
        return self.value * 2

obj = MyClass(10)

# Getting type
print(type(obj)) # <class '__main__.MyClass'>

# Checking instance
print(isinstance(obj, MyClass)) # True

# Getting attribute by name
attr_name = "value"
print(getattr(obj, attr_name)) # 10

# Calling method by name
method_name = "my_method"
method = getattr(obj, method_name)
print(method()) # 20

# Setting a new attribute
setattr(obj, "new_attr", "hello")
print(obj.new_attr) # hello

# Executing code from string
code_string = "print('Executing code from string')"
exec(code_string) # Executing code from string

Table of main reflection functions:

Function	Description
`type()`	Get the type of an object
`isinstance()`	Check if an object is an instance of a class
`issubclass()`	Check if a class is a subclass of another
`getattr()`	Get an attribute
`setattr()`	Set an attribute
`hasattr()`	Check if an attribute exists
`delattr()`	Delete an attribute
`help()`	Interactive help
`__doc__`	Access to the object's docstring
`eval()`	Execute a string as an expression
`exec()`	Execute a string or code object
`dir()`	List of names in the namespace or attributes
`globals()`	Dictionary of global variables
`locals()`	Dictionary of local variables

Used in metaprogramming, debugging, serialization/deserialization, plugin architecture. Use with caution, as it can complicate code understanding and potentially create security issues (eval/exec).