Python ast 模块，Del() 实例源码

def checkGlobalIds(a, l):
    if not isinstance(a, ast.AST):
        return
    elif type(a) in [ ast.Load, ast.Store, ast.Del, ast.AugLoad, ast.AugStore, ast.Param ]:
        return
    if not hasattr(a, "global_id"):
        addedNodes = ["propagatedVariable", "orderedBinOp", 
            "augAssignVal", "augAssignBinOp", 
            "combinedConditional", "combinedConditionalOp", 
            "multiCompPart", "multiCompOp",
            "second_global_id", "moved_line",
            # above this line has individualize functions. below does not.
            "addedNot", "addedNotOp", "addedOther", "addedOtherOp", 
            "collapsedExpr", "removedLines", 
            "helperVar", "helperReturn",
            "typeCastFunction", ]
        for t in addedNodes:
            if hasattr(a, t):
                break
        else: # only enter the else if none of the provided types are an attribute of a
            log("canonicalize\tcheckGlobalIds\tNo global id: " + str(l) + "," + str(a.__dict__) + "," + printFunction(a, 0), "bug")
    for f in ast.iter_child_nodes(a):
        checkGlobalIds(f, l + [type(a)])

def to_source_any(n):
    """
    Convert AST node to string, handling all node types, without fixing comments.
    """
    try:
        return astor.to_source(n)
    except AttributeError:
        pass
    cls = n.__class__
    if cls in astor.misc.all_symbols:
        return astor.misc.all_symbols[cls]
    def wrap(s):
        return '___' + s + '___'
    extra_d = {ast.Load: wrap('load'),
               ast.Store: wrap('store'),
               ast.Del: wrap('del'),
               ast.AugLoad: wrap('augload'),
               ast.AugStore: wrap('augstore'),
               ast.Param: wrap('param'),
               ast.keyword: wrap('keyword')}
    if cls in extra_d:
        return extra_d[cls]
    raise AttributeError('unknown node type {}'.format(cls))

def NAME(self, node):
        """
        Handle occurrence of Name (which can be a load/store/delete access.)
        """
        # Locate the name in locals / function / globals scopes.
        if isinstance(node.ctx, (ast.Load, ast.AugLoad)):
            self.handleNodeLoad(node)
            if (node.id == 'locals' and isinstance(self.scope, FunctionScope)
                    and isinstance(node.parent, ast.Call)):
                # we are doing locals() call in current scope
                self.scope.usesLocals = True
        elif isinstance(node.ctx, (ast.Store, ast.AugStore)):
            self.handleNodeStore(node)
        elif isinstance(node.ctx, ast.Del):
            self.handleNodeDelete(node)
        else:
            # must be a Param context -- this only happens for names in function
            # arguments, but these aren't dispatched through here
            raise RuntimeError("Got impossible expression context: %r" % (node.ctx,))

def NAME(self, node):
        """
        Handle occurrence of Name (which can be a load/store/delete access.)
        """
        # Locate the name in locals / function / globals scopes.
        if isinstance(node.ctx, (ast.Load, ast.AugLoad)):
            self.handleNodeLoad(node)
            if (node.id == 'locals' and isinstance(self.scope, FunctionScope)
                    and isinstance(node.parent, ast.Call)):
                # we are doing locals() call in current scope
                self.scope.usesLocals = True
        elif isinstance(node.ctx, (ast.Store, ast.AugStore)):
            self.handleNodeStore(node)
        elif isinstance(node.ctx, ast.Del):
            self.handleNodeDelete(node)
        else:
            # must be a Param context -- this only happens for names in function
            # arguments, but these aren't dispatched through here
            raise RuntimeError("Got impossible expression context: %r" % (node.ctx,))

def NAME(self, node):
        """
        Handle occurrence of Name (which can be a load/store/delete access.)
        """
        # Locate the name in locals / function / globals scopes.
        if isinstance(node.ctx, (ast.Load, ast.AugLoad)):
            self.handleNodeLoad(node)
            if (node.id == 'locals' and isinstance(self.scope, FunctionScope)
                    and isinstance(node.parent, ast.Call)):
                # we are doing locals() call in current scope
                self.scope.usesLocals = True
        elif isinstance(node.ctx, (ast.Store, ast.AugStore)):
            self.handleNodeStore(node)
        elif isinstance(node.ctx, ast.Del):
            self.handleNodeDelete(node)
        else:
            # must be a Param context -- this only happens for names in function
            # arguments, but these aren't dispatched through here
            raise RuntimeError("Got impossible expression context: %r" % (node.ctx,))

def visit_Name(self, node):
        if isinstance(node.ctx, ast.Load):
            self.loaded.add(node.id)
        elif isinstance(node.ctx, ast.Store):
            self.stored.add(node.id)
        elif isinstance(node.ctx, ast.Del):
            self.deleted.add(node.id)

# Sample usage