What techniques prevent unwanted data read operations?

The following techniques are used in Python to prevent unwanted data reading operations:

• Access control: using private or protected attributes (e.g., with prefixes _ or __) to restrict direct access to data.

• Using properties: defining getters that control when and how data is read.

• Access rights verification: implementing logic to check user permissions before reading data.

• Exception handling: catching attempts to read under inappropriate conditions and raising errors.

• Encryption or masking of data: storing data in encrypted form and decrypting only when access is permitted.

Example using a property to control reading:

class Data:
    def __init__(self):
        self._secret = "secret"
        self._allow_read = False

    @property
    def secret(self):
        if not self._allow_read:
            raise PermissionError("Reading data is forbidden")
        return self._secret

    def enable_read(self):
        self._allow_read = True

    def disable_read(self):
        self._allow_read = False

# Usage
obj = Data()
# obj.secret  # will raise PermissionError
obj.enable_read()
print(obj.secret)  # will output 'secret'