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...Variables are not declared. Names in class scope are not accessible. Names are resolved in the innermost enclosing function scope. If a class definition occurs in a chain of nested scopes, the resolution process skips class definitions. This rule prevents odd interactions between class attributes and local variable access. If a name binding operation occurs in a class definition, it creates an attribute on the resulting class object. To access this variable in a method, or in a function ne...
...definition file for python3.dll [1]. Global Variables Global variables representing types and exceptions are available to applications. In addition, selected global variables referenced in macros (such as Py_True and Py_False) are available. A complete list of global variable definitions is given in the python3.def file [1]; those declared DATA denote variables. Other Macros All macros defining symbolic constants are available to applications; the numeric values will not change. In addition,...
...variable of the compiling structure. This variable defaults to NULL. When it sees a docstring, it then checks the variable and uses the name as basis for the above name mangling to produce an implicit assignment of the docstring to the mangled name. It then resets the variable to NULL to avoid duplicate assignments. If the variable does not point to a name (i.e. is NULL), no assignments are made. These will continue to be ignored like before. All classical docstrings fall under this case, s...
...VARIABLE TYPE="PyObject*" NAME="right"></VARIABLE> <VARIABLE TYPE="PyObject*" NAME="left"></VARIABLE> <VARIABLE TYPE="PyObject*" NAME="expr"></VARIABLE> <CODE_SNIPPET> right = stack_pop(); left = stack_pop(); expr = PyObject_CallMethod(ParsedExpr, "ParsedUnionExpr", "OO", left, right); decref(right); decref(left); stack_push(expr); </CODE_SNIPPET> ...
...variable name given later in the DSL. Additional implicit return values must be prefixed by res_. By default the variables are passed by value to the implementation function. If the address should be passed instead, res must be prefixed with an ampersand. Additional declarations may be placed into .c files. Duplicate declarations are allowed as long as the function types are identical. It is encouraged to declare custom converter types a second time right above the converter function definition....
...definition of the save method would mean that a D instance, when requested to save itself, only saves the A and B parts of its data, but not the part of its data defined by class C! C++ notices that D inherits two conflicting definitions of method m, and issues an error message. The author of D is then supposed to override m to resolve the conflict. But what is D's definition of m supposed to do? It can call B's m followed by C's m, but because both definitions call the definition of...
...variable (it should not be used as part of a larger expression). The argument to TypeVar() must be a string equal to the variable name to which it is assigned. Type variables must not be redefined. TypeVar supports constraining parametric types to a fixed set of possible types (note: those types cannot be parameterized by type variables). For example, we can define a type variable that ranges over just str and bytes. By default, a type variable ranges over all possible types. Example of constr...
...variables are used extensively in type annotations, also internal machinery of the type inference in type checkers is typically build on type variables. Therefore, let us consider them in detail. Type variables X = TypeVar('X') declares a unique type variable. The name must match the variable name. By default, a type variable ranges over all possible types. Example: def do_nothing(one_arg: T, other_arg: T) -> None: pass do_nothing(1, 2) # OK, T is int do_nothing('abc', Us...
...definition is actually a generator) Explaining Decorator Clause Evaluation and Application The standard explanation of decorator clause evaluation and application has to deal with the idea of hidden compiler variables in order to show steps in their order of execution. The given statement allows a decorated function definition like: @classmethod def classname(cls): return cls.__name__ To instead be explained as roughly equivalent to: classname = .d1(classname) given: d1 = classmetho...
...variable. It uses a funny name because the user's instance variables (e.g. self.a later in the example) live in the same namespace. The __getattr__ method is invoked whenever the user code references an attribute of the instance that is not an instance variable (nor a class variable; but except for __init__ and __getattr__ there are no class variables). It will be called, for example, when aninstance.method1 is referenced in the example, with self set to aninstance and name set to th...
...variable defined in the current function scope. An annotation can refer to a local variable defined in an enclosing function scope. An annotation can refer to a class variable defined in the current class scope. An annotation can refer to a global variable. And in all four of these cases, the variable referenced by the annotation needn't be defined at the time the annotation is defined--it can be defined afterwards. The only restriction is that the name or variable be defined before the annota...
...variables. Those variables need to named in such as way as to avoid contaminating the original code and other macros. No rules for naming will be enforced, but to ensure hygiene and help debugging, the following naming scheme is recommended: All generated variable names should start with a $ Purely artificial variable names should start $$mname where mname is the name of the macro. Variables derived from real variables should start $vname where vname is the name of the variable. All variable n...
...definition, class definition, or method definition, after any comments. This is the standard for Python __doc__ attributes. Immediately following a simple assignment at the top level of a module, class definition, or __init__ method definition, after any comments. See Attribute Docstrings below. Additional string literals found immediately after the docstrings in (a) and (b) will be recognized, extracted, and concatenated. See Additional Docstrings below. @@@ 2.2-style "properties" with attri...
...definitions, and major sections inside functions. Comments go before the code they describe. All functions and global variables should be declared static unless they are to be part of a published interface For external functions and variables, we always have a declaration in an appropriate header file in the "Include" directory, which uses the PyAPI_FUNC() macro and PyAPI_DATA() macro, like this: PyAPI_FUNC(PyObject *) PyObject_Repr(PyObject *); PyAPI_DATA(PyTypeObject) PySuper_Type; N...
...variable MUST be considered equivalent to the empty string. If a particular version number value is not available (such as sys.implementation.version in versions of Python prior to 3.3) the corresponding marker variable MUST be considered equivalent to 0 Version numbers python_version: platform.python_version()[:3] python_full_version: see definition below platform_version: platform.version() implementation_version: see definition below The python_full_version and implementation_version mark...
...variables. Alternatively, if we choose (b) above, we could choose this implementation inside a class definition as well. Option 4 There are a number of proposals to add a construct to the language that makes the concept of a value pre-computed at function definition time generally available, without tying it either to parameter default values or case expressions. Some keywords proposed include 'const', 'static', 'only' or 'cached'. The associated syntax and semantics vary. These proposals ar...
...variable is declared with the var keyword; undeclared variable names are assumed to be global. In Perl, a lexically scoped variable is declared with the my keyword; undeclared variable names are assumed to be global. In Scheme, all variables must be declared (with define or let, or as formal parameters). In Smalltalk, any block can begin by declaring a list of local variable names between vertical bars. C and C# require type declarations for all variables. For all these cases, the variable b...