Python MCQs with explanation

Which of the following declarations is incorrect?

1. _x = 2
2.  __x = 3
3. __xyz__ = 5
4. None of these

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Answer: 

Option d: None of these

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In Python, variables can start with an underscore or double underscore without any issues. The single underscore prefix is commonly used as a convention to indicate that a variable is intended for internal use or as a placeholder.

The double underscore prefix is used for name mangling, primarily to avoid naming conflicts in subclasses.

The line of code _ _x_ _ = 3 in Python indicates that the variable _ _ _x__ is assigned the value 3. The double underscores (__) before and after the variable name indicate that it is a private variable. Private variables are not accessible outside of the class or module in which they are defined.