mirror of https://github.com/python/cpython
179 lines
4.6 KiB
ReStructuredText
179 lines
4.6 KiB
ReStructuredText
:mod:`symtable` --- Access to the compiler's symbol tables
|
|
==========================================================
|
|
|
|
.. module:: symtable
|
|
:synopsis: Interface to the compiler's internal symbol tables.
|
|
|
|
.. moduleauthor:: Jeremy Hylton <jeremy@alum.mit.edu>
|
|
.. sectionauthor:: Benjamin Peterson <benjamin@python.org>
|
|
|
|
|
|
Symbol tables are generated by the compiler from AST just before bytecode is
|
|
generated. The symbol table is responsible for calculating the scope of every
|
|
identifier in the code. :mod:`symtable` provides an interface to examine these
|
|
tables.
|
|
|
|
|
|
Generating Symbol Tables
|
|
------------------------
|
|
|
|
.. function:: symtable(code, filename, compile_type)
|
|
|
|
Return the toplevel :class:`SymbolTable` for the Python source *code*.
|
|
*filename* is the name of the file containing the code. *compile_type* is
|
|
like the *mode* argument to :func:`compile`.
|
|
|
|
|
|
Examining Symbol Tables
|
|
-----------------------
|
|
|
|
.. class:: SymbolTable
|
|
|
|
A namespace table for a block. The constructor is not public.
|
|
|
|
.. method:: get_type()
|
|
|
|
Return the type of the symbol table. Possible values are ``'class'``,
|
|
``'module'``, and ``'function'``.
|
|
|
|
.. method:: get_id()
|
|
|
|
Return the table's identifier.
|
|
|
|
.. method:: get_name()
|
|
|
|
Return the table's name. This is the name of the class if the table is
|
|
for a class, the name of the function if the table is for a function, or
|
|
``'top'`` if the table is global (:meth:`get_type` returns ``'module'``).
|
|
|
|
.. method:: get_lineno()
|
|
|
|
Return the number of the first line in the block this table represents.
|
|
|
|
.. method:: is_optimized()
|
|
|
|
Return ``True`` if the locals in this table can be optimized.
|
|
|
|
.. method:: is_nested()
|
|
|
|
Return ``True`` if the block is a nested class or function.
|
|
|
|
.. method:: has_children()
|
|
|
|
Return ``True`` if the block has nested namespaces within it. These can
|
|
be obtained with :meth:`get_children`.
|
|
|
|
.. method:: has_exec()
|
|
|
|
Return ``True`` if the block uses ``exec``.
|
|
|
|
.. method:: has_import_start()
|
|
|
|
Return ``True`` if the block uses a starred from-import.
|
|
|
|
.. method:: get_identifiers()
|
|
|
|
Return a list of names of symbols in this table.
|
|
|
|
.. method:: lookup(name)
|
|
|
|
Lookup *name* in the table and return a :class:`Symbol` instance.
|
|
|
|
.. method:: get_symbols()
|
|
|
|
Return a list of :class:`Symbol` instances for names in the table.
|
|
|
|
.. method:: get_children()
|
|
|
|
Return a list of the nested symbol tables.
|
|
|
|
|
|
.. class:: Function
|
|
|
|
A namespace for a function or method. This class inherits
|
|
:class:`SymbolTable`.
|
|
|
|
.. method:: get_parameters()
|
|
|
|
Return a tuple containing names of parameters to this function.
|
|
|
|
.. method:: get_locals()
|
|
|
|
Return a tuple containing names of locals in this function.
|
|
|
|
.. method:: get_globals()
|
|
|
|
Return a tuple containing names of globals in this function.
|
|
|
|
.. method:: get_frees()
|
|
|
|
Return a tuple containing names of free variables in this function.
|
|
|
|
|
|
.. class:: Class
|
|
|
|
A namespace of a class. This class inherits :class:`SymbolTable`.
|
|
|
|
.. method:: get_methods()
|
|
|
|
Return a tuple containing the names of methods declared in the class.
|
|
|
|
|
|
.. class:: Symbol
|
|
|
|
An entry in a :class:`SymbolTable` corresponding to an identifier in the
|
|
source. The constructor is not public.
|
|
|
|
.. method:: get_name()
|
|
|
|
Return the symbol's name.
|
|
|
|
.. method:: is_referenced()
|
|
|
|
Return ``True`` if the symbol is used in its block.
|
|
|
|
.. method:: is_imported()
|
|
|
|
Return ``True`` if the symbol is created from an import statement.
|
|
|
|
.. method:: is_parameter()
|
|
|
|
Return ``True`` if the symbol is a parameter.
|
|
|
|
.. method:: is_global()
|
|
|
|
Return ``True`` if the symbol is global.
|
|
|
|
.. method:: is_local()
|
|
|
|
Return ``True`` if the symbol is local to its block.
|
|
|
|
.. method:: is_free()
|
|
|
|
Return ``True`` if the symbol is referenced in its block, but not assigned
|
|
to.
|
|
|
|
.. method:: is_assigned()
|
|
|
|
Return ``True`` if the symbol is assigned to in its block.
|
|
|
|
.. method:: is_namespace()
|
|
|
|
Return ``True`` if name binding introduces new namespace.
|
|
|
|
If the name is used as the target of a function or class statement, this
|
|
will be true.
|
|
|
|
Note that a single name can be bound to multiple objects. If the result
|
|
is ``True``, the name may also be bound to other objects, like an int or
|
|
list, that does not introduce a new namespace.
|
|
|
|
.. method:: get_namespaces()
|
|
|
|
Return a list of namespaces bound to this name.
|
|
|
|
.. method:: get_namespace()
|
|
|
|
Return the namespace bound to this name. If more than one namespace is
|
|
bound, a :exc:`ValueError` is raised.
|