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In Python, namespaces are defined by the individual modules, and since modules can be contained in hierarchical packages, then namespaces are hierarchical too. [ 12 ] [ 13 ] In general when a module is imported then the names defined in the module are defined via that module's namespace, and are accessed in from the calling modules by using the ...
In computer programming, scope is an enclosing context where values and expressions are associated. The scope resolution operator helps to identify and specify the context to which an identifier refers, particularly by specifying a namespace or class. The specific uses vary across different programming languages with the notions of scoping.
Static name resolution catches, at compile time, use of variables that are not in scope; preventing programmer errors. Languages with dynamic scope resolution sacrifice this safety for more flexibility; they can typically set and get variables in the same scope at runtime. For example, in the Python interactive REPL:
In Python, auxiliary variables in generator expressions and list comprehensions (in Python 3) have expression scope. In C, variable names in a function prototype have expression scope, known in this context as function protocol scope. As the variable names in the prototype are not referred to (they may be different in the actual definition ...
In computer programming, variable shadowing occurs when a variable declared within a certain scope (decision block, method, or inner class) has the same name as a variable declared in an outer scope. At the level of identifiers (names, rather than variables), this is known as name masking.
The scope of anonymous classes is confined to their parent class, so the compiler must produce a "qualified" public name for the inner class, to avoid conflict where other classes with the same name (inner or not) exist in the same namespace. Similarly, anonymous classes must have "fake" public names generated for them (as the concept of ...
In Python, if a name is intended to be "private", it is prefixed by one or two underscores. Private variables are enforced in Python only by convention. Names can also be suffixed with an underscore to prevent conflict with Python keywords. Prefixing with double underscores changes behaviour in classes with regard to name mangling.
Similarly, a reference to "*USR:X" would mean the file in their own library, and "MA45:X" would be a fully qualified file name referring to the specific file X in the library of user MA45. On the RSTS/E operating system on the PDP-11 minicomputer, specifying a file "X.X" would refer to a file in one's own directory.