Protected and Unprotected Variables in python

In Python, variables can be protected or unprotected, depending on the naming convention used.

Protected variables in Python are variables whose names start with a single underscore character (_). They are meant to indicate that the variable is intended for internal use only and should not be accessed from outside the class or module. However, they can still be accessed from outside the class or module if the user explicitly calls them..

Unprotected variables, on the other hand, have names that do not start with an underscore character. They can be accessed and modified from outside the class or module without any restrictions.

It's important to note that the use of protected variables in Python is more of a convention than a strict rule, and it's up to the developer to decide how to use them in their code. Protected variables can still be accessed and modified from outside the class or module, so they don't provide true encapsulation or data hiding. If you need to prevent external access to variables, you should use private variables, which are declared with two underscores (__) before the variable name.

The example below shows a program where this is demonstrasted, we will develop a diary system as shown.

In this implementation, the _password variable is protected by convention (note the leading underscore), meaning it should not be accessed directly by client code. Instead, it can be set and accessed via the set_password() method. The entry variable is an unprotected variable that can be accessed and modified directly.

The add_entry() method allows a new entry to be added to the diary. If a password has been set, it must be provided as an argument to the method. If the password is correct, the entry is added to the entry variable. If the password is incorrect, the method returns an error message.

The read_entries() method allows the diary entries to be read. Again, if a password has been set, it must be provided as an argument. If the password is correct, the entries are printed to the console. If the password is incorrect, the method returns an error message.

Module self reflection

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The module detailed more about classes and their design and best practices. I am now able to design classes based on best practices as outlined in this module. I know there is much to learn but this has laid a better foundation for me as I go forward.

I now know about various kinds of data types to variables in python programming. Overall this module has really introduced the building blocks of object oriented programming.