Python Class Privacy Manipulation: Revealing and Concealing Characteristics
Name Mangling in Python: A Convention for Weak Privacy
In the realm of Python programming, the terms "public" and "private" are used to describe the accessibility of classes' methods and attributes. Unlike some programming languages, Python does not have a strict private keyword, but it offers pseudo-privacy through two levels: indication privacy and hide-and-seek privacy.
When a method or attribute is marked as private, it should not be called or used outside the class. In Python, this is achieved by adding a leading underscore to the name, such as . This serves as a suggestion to users not to access the private element, but Python does not enforce this rule strictly.
Name mangling is a convention-based technique that helps protect private attributes and methods by changing their names internally to include the class name, reducing the risk of accidental misuse but not making them completely inaccessible. For example, an attribute named in a class is internally changed to . This prevents accidental access from outside the class or from subclasses.
```python class A: def __private_method(self): print("Private method")
obj = A() obj._A__private_method() # Accesses the "private" method via name mangling ```
Output:
In indication privacy, private attributes and methods are suggested to be treated as such but are not hidden from the user. This mechanism supports encapsulation in Python, which lacks a true private keyword, by discouraging casual access while still allowing deliberate access when needed.
On the other hand, hide-and-seek privacy aims to make it harder for the user to access private attributes from outside the class through name mangling. However, this level of privacy is not natively supported in Python.
An interesting fact about Python is that strings are iterables, meaning you can add them to a list, but they are treated as an iterable of their individual characters, and it is these characters that are added to the list, not the word itself.
Lastly, it's worth noting that methods in Python are simply attributes of the class. The in-place concatenation, , works in Python by adding two lists, a tuple, a set, or a generator; it does not work for non-iterable objects like numbers.
In conclusion, name mangling is a valuable tool for Python developers, offering a weak form of privacy for attributes and methods, but it does not provide complete protection. Users should be aware of this convention and exercise caution when dealing with private elements in Python code.
Whilst name mangling offers a convention-based technique for protecting private attributes and methods in Python, it does not enforce secrecy strictly, thus it's essential for users to be mindful of this practice when handling private elements.
Moreover, name mangling in Python helps make private attributes and methods less accessible by altering their names internally to include the class name, reducing the likelihood of accidental misuse but providing only a form of weak privacy.
