Generating Symbol Tables¶

symtable.symtable(code,filename,compile_type)¶

Return the toplevelSymbolTable for the Python sourcecode.filename is the name of the file containing the code.compile_type islike themode argument tocompile().

Examining Symbol Tables¶

classsymtable.SymbolTableType¶

An enumeration indicating the type of aSymbolTable object.

MODULE="module"¶

Used for the symbol table of a module.

FUNCTION="function"¶

Used for the symbol table of a function.

CLASS="class"¶

Used for the symbol table of a class.

The following members refer to different flavors ofannotation scopes.

ANNOTATION="annotation"¶

Used for annotations iffrom__future__importannotations is active.

TYPE_ALIAS="typealias"¶

Used for the symbol table oftype constructions.

TYPE_PARAMETERS="typeparameters"¶

Used for the symbol table ofgeneric functionsorgeneric classes.

TYPE_VARIABLE="typevariable"¶

Used for the symbol table of the bound, the constraint tuple or thedefault value of a single type variable in the formal sense, i.e.,a TypeVar, a TypeVarTuple or a ParamSpec object (the latter two donot support a bound or a constraint tuple).

Added in version 3.13.

classsymtable.SymbolTable¶

A namespace table for a block. The constructor is not public.

get_type()¶

Return the type of the symbol table. Possible values are membersof theSymbolTableType enumeration.

Changed in version 3.12:Added'annotation','TypeVarbound','typealias',and'typeparameter' as possible return values.

Changed in version 3.13:Return values are members of theSymbolTableType enumeration.

The exact values of the returned string may change in the future,and thus, it is recommended to useSymbolTableType membersinstead of hard-coded strings.

get_id()¶

Return the table’s identifier.

get_name()¶

Return the table’s name. This is the name of the class if the table isfor a class, the name of the function if the table is for a function, or'top' if the table is global (get_type() returns'module').For type parameter scopes (which are used for generic classes, functions,and type aliases), it is the name of the underlying class, function, ortype alias. For type alias scopes, it is the name of the type alias.ForTypeVar bound scopes, it is the name of theTypeVar.

get_lineno()¶

Return the number of the first line in the block this table represents.

is_optimized()¶

ReturnTrue if the locals in this table can be optimized.

is_nested()¶

ReturnTrue if the block is a nested class or function.

has_children()¶

ReturnTrue if the block has nested namespaces within it. These canbe obtained withget_children().

get_identifiers()¶

Return a view object containing the names of symbols in the table.See thedocumentation of view objects.

lookup(name)¶

Lookupname in the table and return aSymbol instance.

get_symbols()¶

Return a list ofSymbol instances for names in the table.

get_children()¶

Return a list of the nested symbol tables.

classsymtable.Function¶

A namespace for a function or method. This class inherits fromSymbolTable.

get_parameters()¶

Return a tuple containing names of parameters to this function.

get_locals()¶

Return a tuple containing names of locals in this function.

get_globals()¶

Return a tuple containing names of globals in this function.

get_nonlocals()¶

Return a tuple containing names of explicitly declared nonlocals in this function.

get_frees()¶

Return a tuple containing names offree (closure) variablesin this function.

classsymtable.Class¶

A namespace of a class. This class inherits fromSymbolTable.

get_methods()¶

Return a tuple containing the names of method-like functions declaredin the class.

Here, the term ‘method’ designatesany function defined in the classbody viadef orasyncdef.

Functions defined in a deeper scope (e.g., in an inner class) are notpicked up byget_methods().

For example:

>>>importsymtable>>>st=symtable.symtable('''...def outer(): pass......class A:...   def f():...       def w(): pass......   def g(self): pass......   @classmethod...   async def h(cls): pass......   global outer...   def outer(self): pass...''','test','exec')>>>class_A=st.get_children()[1]>>>class_A.get_methods()('f', 'g', 'h')

AlthoughA().f() raisesTypeError at runtime,A.f is stillconsidered as a method-like function.

classsymtable.Symbol¶

An entry in aSymbolTable corresponding to an identifier in thesource. The constructor is not public.

get_name()¶

Return the symbol’s name.

is_referenced()¶

ReturnTrue if the symbol is used in its block.

is_imported()¶

ReturnTrue if the symbol is created from an import statement.

is_parameter()¶

ReturnTrue if the symbol is a parameter.

is_global()¶

ReturnTrue if the symbol is global.

is_nonlocal()¶

ReturnTrue if the symbol is nonlocal.

is_declared_global()¶

ReturnTrue if the symbol is declared global with a global statement.

is_local()¶

ReturnTrue if the symbol is local to its block.

is_annotated()¶

ReturnTrue if the symbol is annotated.

Added in version 3.6.

is_free()¶

ReturnTrue if the symbol is referenced in its block, but not assignedto.

is_assigned()¶

ReturnTrue if the symbol is assigned to in its block.

is_namespace()¶

ReturnTrue if name binding introduces new namespace.

If the name is used as the target of a function or class statement, thiswill be true.

For example:

>>>table=symtable.symtable("def some_func(): pass","string","exec")>>>table.lookup("some_func").is_namespace()True

Note that a single name can be bound to multiple objects. If the resultisTrue, the name may also be bound to other objects, like an int orlist, that does not introduce a new namespace.

get_namespaces()¶

Return a list of namespaces bound to this name.

get_namespace()¶

Return the namespace bound to this name. If more than one or no namespaceis bound to this name, aValueError is raised.

Command-Line Usage¶

Thesymtable module can be executed as a script from the command line.

python-msymtable[infile...]

Symbol tables are generated for the specified Python source files anddumped to stdout.If no input file is specified, the content is read from stdin.