Python ast.stmt() Examples

def visit(self, node):
        if isinstance(node, (ast.expr, ast.stmt)):
            self.last_line = node.lineno

        # do nothing for root
        if not self.stack:
            return self._visit_children(node)

        annotation = self.stack[-1]

        # this is a standalone string, may be an annotation
        if type(node) is ast.Expr and type(node.value) is ast.Str:
            # must not annotate an annotation string
            assert annotation is None, 'Annotating an annotation'
            return self._visit_string(node)

        if annotation is not None:  # this expression is annotated
            self.stack[-1] = None  # so next expression is not
            if annotation.startswith('nni.variable'):
                return replace_variable_node(node, annotation)
            if annotation.startswith('nni.function_choice'):
                return replace_function_node(node, annotation)

        return self._visit_children(node) 

def test_classdef(self):
        def cls(bases=None, keywords=None, body=None, decorator_list=None):
            if bases is None:
                bases = []
            if keywords is None:
                keywords = []
            if body is None:
                body = [ast.Pass()]
            if decorator_list is None:
                decorator_list = []
            return ast.ClassDef("myclass", bases, keywords,
                                body, decorator_list)
        self.stmt(cls(bases=[ast.Name("x", ast.Store())]),
                  "must have Load context")
        self.stmt(cls(keywords=[ast.keyword("x", ast.Name("x", ast.Store()))]),
                  "must have Load context")
        self.stmt(cls(body=[]), "empty body on ClassDef")
        self.stmt(cls(body=[None]), "None disallowed")
        self.stmt(cls(decorator_list=[ast.Name("x", ast.Store())]),
                  "must have Load context") 

def __exit_scope(self) -> ast.stmt:
        """Create the appropriate scope exiting statement.

        The documentation only shows one level and always uses
        'return False' in examples.

        'raise AltFalse()' within a try.
        'break' within a loop.
        'return False' otherwise.
        """
        if self.in_optional:
            return ast.Pass()
        if self.in_try:
            return ast.Raise(
                ast.Call(ast.Name('AltFalse', ast.Load()), [], [], None, None),
                None)
        if self.in_loop:
            return ast.Break()
        return ast.Return(ast.Name('False', ast.Load()))

    #TODO(bps): find a better name to describe what this does 

def visit_Rep0N(self, node: parsing.Rep0N) -> [ast.stmt]:
        """Generates python code for a clause repeated 0 or more times.

        #If all clauses can be inlined
        while clause:
            pass

        while True:
            <code for the clause>
        """
        cl_ast = self.visit(node.pt)
        if isinstance(cl_ast, ast.expr):
            return [ast.While(cl_ast, [ast.Pass()], [])]
        self.in_loop += 1
        clause = self._clause(self.visit(node.pt))
        self.in_loop -= 1
        return [ast.While(ast.Name('True', ast.Load()), clause, [])] 

def test_classdef(self):
        def cls(bases=None, keywords=None, starargs=None, kwargs=None,
                body=None, decorator_list=None):
            if bases is None:
                bases = []
            if keywords is None:
                keywords = []
            if body is None:
                body = [ast.Pass()]
            if decorator_list is None:
                decorator_list = []
            return ast.ClassDef("myclass", bases, keywords, starargs,
                                kwargs, body, decorator_list)
        self.stmt(cls(bases=[ast.Name("x", ast.Store())]),
                  "must have Load context")
        self.stmt(cls(keywords=[ast.keyword("x", ast.Name("x", ast.Store()))]),
                  "must have Load context")
        self.stmt(cls(starargs=ast.Name("x", ast.Store())),
                  "must have Load context")
        self.stmt(cls(kwargs=ast.Name("x", ast.Store())),
                  "must have Load context")
        self.stmt(cls(body=[]), "empty body on ClassDef")
        self.stmt(cls(body=[None]), "None disallowed")
        self.stmt(cls(decorator_list=[ast.Name("x", ast.Store())]),
                  "must have Load context") 

def test_try(self):
        p = ast.Pass()
        t = ast.Try([], [], [], [p])
        self.stmt(t, "empty body on Try")
        t = ast.Try([ast.Expr(ast.Name("x", ast.Store()))], [], [], [p])
        self.stmt(t, "must have Load context")
        t = ast.Try([p], [], [], [])
        self.stmt(t, "Try has neither except handlers nor finalbody")
        t = ast.Try([p], [], [p], [p])
        self.stmt(t, "Try has orelse but no except handlers")
        t = ast.Try([p], [ast.ExceptHandler(None, "x", [])], [], [])
        self.stmt(t, "empty body on ExceptHandler")
        e = [ast.ExceptHandler(ast.Name("x", ast.Store()), "y", [p])]
        self.stmt(ast.Try([p], e, [], []), "must have Load context")
        e = [ast.ExceptHandler(None, "x", [p])]
        t = ast.Try([p], e, [ast.Expr(ast.Name("x", ast.Store()))], [p])
        self.stmt(t, "must have Load context")
        t = ast.Try([p], e, [p], [ast.Expr(ast.Name("x", ast.Store()))])
        self.stmt(t, "must have Load context") 

def get_statement_startend2(lineno, node):
    import ast

    # flatten all statements and except handlers into one lineno-list
    # AST's line numbers start indexing at 1
    values = []
    for x in ast.walk(node):
        if isinstance(x, (ast.stmt, ast.ExceptHandler)):
            values.append(x.lineno - 1)
            for name in ("finalbody", "orelse"):
                val = getattr(x, name, None)
                if val:
                    # treat the finally/orelse part as its own statement
                    values.append(val[0].lineno - 1 - 1)
    values.sort()
    insert_index = bisect_right(values, lineno)
    start = values[insert_index - 1]
    if insert_index >= len(values):
        end = None
    else:
        end = values[insert_index]
    return start, end 

def test_try(self):
        p = ast.Pass()
        t = ast.Try([], [], [], [p])
        self.stmt(t, "empty body on Try")
        t = ast.Try([ast.Expr(ast.Name("x", ast.Store()))], [], [], [p])
        self.stmt(t, "must have Load context")
        t = ast.Try([p], [], [], [])
        self.stmt(t, "Try has neither except handlers nor finalbody")
        t = ast.Try([p], [], [p], [p])
        self.stmt(t, "Try has orelse but no except handlers")
        t = ast.Try([p], [ast.ExceptHandler(None, "x", [])], [], [])
        self.stmt(t, "empty body on ExceptHandler")
        e = [ast.ExceptHandler(ast.Name("x", ast.Store()), "y", [p])]
        self.stmt(ast.Try([p], e, [], []), "must have Load context")
        e = [ast.ExceptHandler(None, "x", [p])]
        t = ast.Try([p], e, [ast.Expr(ast.Name("x", ast.Store()))], [p])
        self.stmt(t, "must have Load context")
        t = ast.Try([p], e, [p], [ast.Expr(ast.Name("x", ast.Store()))])
        self.stmt(t, "must have Load context") 

def get_statement_startend2(lineno: int, node: ast.AST) -> Tuple[int, Optional[int]]:
    # flatten all statements and except handlers into one lineno-list
    # AST's line numbers start indexing at 1
    values = []  # type: List[int]
    for x in ast.walk(node):
        if isinstance(x, (ast.stmt, ast.ExceptHandler)):
            values.append(x.lineno - 1)
            for name in ("finalbody", "orelse"):
                val = getattr(x, name, None)  # type: Optional[List[ast.stmt]]
                if val:
                    # treat the finally/orelse part as its own statement
                    values.append(val[0].lineno - 1 - 1)
    values.sort()
    insert_index = bisect_right(values, lineno)
    start = values[insert_index - 1]
    if insert_index >= len(values):
        end = None
    else:
        end = values[insert_index]
    return start, end 

def get_statement_startend2(lineno, node):
    import ast

    # flatten all statements and except handlers into one lineno-list
    # AST's line numbers start indexing at 1
    values = []
    for x in ast.walk(node):
        if isinstance(x, (ast.stmt, ast.ExceptHandler)):
            values.append(x.lineno - 1)
            for name in ("finalbody", "orelse"):
                val = getattr(x, name, None)
                if val:
                    # treat the finally/orelse part as its own statement
                    values.append(val[0].lineno - 1 - 1)
    values.sort()
    insert_index = bisect_right(values, lineno)
    start = values[insert_index - 1]
    if insert_index >= len(values):
        end = None
    else:
        end = values[insert_index]
    return start, end 

def visit_Module(self, mod):
        for stmt in mod.body:
            self.visit(stmt) 

def test_importfrom(self):
        imp = ast.ImportFrom(None, [ast.alias("x", None)], -42)
        self.stmt(imp, "level less than -1")
        self.stmt(ast.ImportFrom(None, [], 0), "empty names on ImportFrom") 

def _assertTrueorder(self, ast_node, parent_pos):
        if not isinstance(ast_node, ast.AST) or ast_node._fields is None:
            return
        if isinstance(ast_node, (ast.expr, ast.stmt, ast.excepthandler)):
            node_pos = (ast_node.lineno, ast_node.col_offset)
            self.assertTrue(node_pos >= parent_pos)
            parent_pos = (ast_node.lineno, ast_node.col_offset)
        for name in ast_node._fields:
            value = getattr(ast_node, name)
            if isinstance(value, list):
                for child in value:
                    self._assertTrueorder(child, parent_pos)
            elif value is not None:
                self._assertTrueorder(value, parent_pos) 

def test_base_classes(self):
        self.assertTrue(issubclass(ast.For, ast.stmt))
        self.assertTrue(issubclass(ast.Name, ast.expr))
        self.assertTrue(issubclass(ast.stmt, ast.AST))
        self.assertTrue(issubclass(ast.expr, ast.AST))
        self.assertTrue(issubclass(ast.comprehension, ast.AST))
        self.assertTrue(issubclass(ast.Gt, ast.AST)) 

def test_nonlocal(self):
        self.stmt(ast.Nonlocal([]), "empty names on Nonlocal") 

def test_starred(self):
        left = ast.List([ast.Starred(ast.Name("x", ast.Load()), ast.Store())],
                        ast.Store())
        assign = ast.Assign([left], ast.Num(4))
        self.stmt(assign, "must have Store context") 

def test_expr(self):
        e = ast.Expr(ast.Name("x", ast.Store()))
        self.stmt(e, "must have Load context") 

def _assertTrueorder(self, ast_node, parent_pos):
        if not isinstance(ast_node, ast.AST) or ast_node._fields is None:
            return
        if isinstance(ast_node, (ast.expr, ast.stmt, ast.excepthandler)):
            node_pos = (ast_node.lineno, ast_node.col_offset)
            self.assertTrue(node_pos >= parent_pos)
            parent_pos = (ast_node.lineno, ast_node.col_offset)
        for name in ast_node._fields:
            value = getattr(ast_node, name)
            if isinstance(value, list):
                for child in value:
                    self._assertTrueorder(child, parent_pos)
            elif value is not None:
                self._assertTrueorder(value, parent_pos) 

def test_for(self):
        x = ast.Name("x", ast.Store())
        y = ast.Name("y", ast.Load())
        p = ast.Pass()
        self.stmt(ast.For(x, y, [], []), "empty body on For")
        self.stmt(ast.For(ast.Name("x", ast.Load()), y, [p], []),
                  "must have Store context")
        self.stmt(ast.For(x, ast.Name("y", ast.Store()), [p], []),
                  "must have Load context")
        e = ast.Expr(ast.Name("x", ast.Store()))
        self.stmt(ast.For(x, y, [e], []), "must have Load context")
        self.stmt(ast.For(x, y, [p], [e]), "must have Load context") 

def _is_ast_stmt(node):
        return isinstance(node, ast.stmt) 

def test_starred(self):
        left = ast.List([ast.Starred(ast.Name("x", ast.Load()), ast.Store())],
                        ast.Store())
        assign = ast.Assign([left], ast.Num(4))
        self.stmt(assign, "must have Store context") 

def test_expr(self):
        e = ast.Expr(ast.Name("x", ast.Store()))
        self.stmt(e, "must have Load context") 

def test_nonlocal(self):
        self.stmt(ast.Nonlocal([]), "empty names on Nonlocal") 

def test_importfrom(self):
        imp = ast.ImportFrom(None, [ast.alias("x", None)], -42)
        self.stmt(imp, "level less than -1")
        self.stmt(ast.ImportFrom(None, [], 0), "empty names on ImportFrom") 

def test_import(self):
        self.stmt(ast.Import([]), "empty names on Import") 

def test_assert(self):
        self.stmt(ast.Assert(ast.Name("x", ast.Store()), None),
                  "must have Load context")
        assrt = ast.Assert(ast.Name("x", ast.Load()),
                           ast.Name("y", ast.Store()))
        self.stmt(assrt, "must have Load context") 

def test_raise(self):
        r = ast.Raise(None, ast.Num(3))
        self.stmt(r, "Raise with cause but no exception")
        r = ast.Raise(ast.Name("x", ast.Store()), None)
        self.stmt(r, "must have Load context")
        r = ast.Raise(ast.Num(4), ast.Name("x", ast.Store()))
        self.stmt(r, "must have Load context") 

def test_if(self):
        self.stmt(ast.If(ast.Num(3), [], []), "empty body on If")
        i = ast.If(ast.Name("x", ast.Store()), [ast.Pass()], [])
        self.stmt(i, "must have Load context")
        i = ast.If(ast.Num(3), [ast.Expr(ast.Name("x", ast.Store()))], [])
        self.stmt(i, "must have Load context")
        i = ast.If(ast.Num(3), [ast.Pass()],
                   [ast.Expr(ast.Name("x", ast.Store()))])
        self.stmt(i, "must have Load context") 

def test_while(self):
        self.stmt(ast.While(ast.Num(3), [], []), "empty body on While")
        self.stmt(ast.While(ast.Name("x", ast.Store()), [ast.Pass()], []),
                  "must have Load context")
        self.stmt(ast.While(ast.Num(3), [ast.Pass()],
                             [ast.Expr(ast.Name("x", ast.Store()))]),
                             "must have Load context") 

def test_funcdef(self):
        a = ast.arguments([], None, [], [], None, [])
        f = ast.FunctionDef("x", a, [], [], None)
        self.stmt(f, "empty body on FunctionDef")
        f = ast.FunctionDef("x", a, [ast.Pass()], [ast.Name("x", ast.Store())],
                            None)
        self.stmt(f, "must have Load context")
        f = ast.FunctionDef("x", a, [ast.Pass()], [],
                            ast.Name("x", ast.Store()))
        self.stmt(f, "must have Load context")
        def fac(args):
            return ast.FunctionDef("x", args, [ast.Pass()], [], None)
        self._check_arguments(fac, self.stmt)