Context Variables Objects¶

// in 3.7.0:PyContext*PyContext_New(void);// in 3.7.1+:PyObject*PyContext_New(void);

This section details the public C API for thecontextvars module.

PyContext¶

The C structure used to represent acontextvars.Contextobject.

PyContextVar¶

The C structure used to represent acontextvars.ContextVarobject.

PyContextToken¶

The C structure used to represent acontextvars.Token object.

PyTypeObjectPyContext_Type¶

The type object representing thecontext type.

PyTypeObjectPyContextVar_Type¶

The type object representing thecontext variable type.

PyTypeObjectPyContextToken_Type¶

The type object representing thecontext variable token type.

Type-check macros:

intPyContext_CheckExact(PyObject *o)¶

Return true ifo is of typePyContext_Type.o must not beNULL. This function always succeeds.

intPyContextVar_CheckExact(PyObject *o)¶

Return true ifo is of typePyContextVar_Type.o must not beNULL. This function always succeeds.

intPyContextToken_CheckExact(PyObject *o)¶

Return true ifo is of typePyContextToken_Type.o must not beNULL. This function always succeeds.

Context object management functions:

PyObject *PyContext_New(void)¶

Return value: New reference.

Create a new empty context object. ReturnsNULL if an errorhas occurred.

PyObject *PyContext_Copy(PyObject *ctx)¶

Return value: New reference.

Create a shallow copy of the passedctx context object.ReturnsNULL if an error has occurred.

PyObject *PyContext_CopyCurrent(void)¶

Return value: New reference.

Create a shallow copy of the current thread context.ReturnsNULL if an error has occurred.

intPyContext_Enter(PyObject *ctx)¶

Setctx as the current context for the current thread.Returns0 on success, and-1 on error.

intPyContext_Exit(PyObject *ctx)¶

Deactivate thectx context and restore the previous context as thecurrent context for the current thread. Returns0 on success,and-1 on error.

intPyContext_ClearFreeList()¶

Clear the context variable free list. Return the total number offreed items. This function always succeeds.

Context variable functions:

PyObject *PyContextVar_New(const char *name,PyObject *def)¶

Return value: New reference.

Create a newContextVar object. Thename parameter is usedfor introspection and debug purposes. Thedef parameter may optionallyspecify the default value for the context variable. If an error hasoccurred, this function returnsNULL.

intPyContextVar_Get(PyObject *var,PyObject *default_value,PyObject **value)¶

Get the value of a context variable. Returns-1 if an error hasoccurred during lookup, and0 if no error occurred, whether or nota value was found.

If the context variable was found,value will be a pointer to it.If the context variable wasnot found,value will point to:

• default_value, if notNULL;

• the default value ofvar, if notNULL;

• NULL

If the value was found, the function will create a new reference to it.

PyObject *PyContextVar_Set(PyObject *var,PyObject *value)¶

Return value: New reference.

Set the value ofvar tovalue in the current context. Returns apointer to aPyObject object, orNULL if an errorhas occurred.

intPyContextVar_Reset(PyObject *var,PyObject *token)¶

Reset the state of thevar context variable to that it was in beforePyContextVar_Set() that returned thetoken was called.This function returns0 on success and-1 on error.