Python ast 模块，Pow() 实例源码

def _is_numeric_pow(self, node: ast.BinOp) -> bool:
        if isinstance(node.op, ast.Pow):
            left, right = node.left, node.right
            if isinstance(left, (ast.Name, ast.Num)):
                if isinstance(right, ast.Num):
                    degree = right.n
                elif isinstance(right, ast.UnaryOp)\
                and  isinstance(right.op, (ast.USub, ast.UAdd))\
                and  isinstance(right.operand, ast.Num):
                    degree = right.operand.n
                else:
                    return False
                if isinstance(degree, float):
                    degree = int(degree) if degree.is_integer() else degree
                return isinstance(degree, int)
        return False

def num_negate(op):
    top = type(op)
    neg = not op.num_negated if hasattr(op, "num_negated") else True
    if top == ast.Add:
        newOp = ast.Sub()
    elif top == ast.Sub:
        newOp = ast.Add()
    elif top in [ast.Mult, ast.Div, ast.Mod, ast.Pow, ast.LShift, 
                 ast.RShift, ast.BitOr, ast.BitXor, ast.BitAnd, ast.FloorDiv]:
        return None # can't negate this
    elif top in [ast.Num, ast.Name]:
        # this is a normal value, so put a - in front of it
        newOp = ast.UnaryOp(ast.USub(addedNeg=True), op)
    else:
        log("astTools\tnum_negate\tUnusual type: " + str(top), "bug")
    transferMetaData(op, newOp)
    newOp.num_negated = neg
    return newOp

def visit_AugAssign(self, node):
        """
        AugAssign(expr target, operator op, expr value)
        """
        # TODO: Make sure that all the logic in Assign also works in AugAssign
        target = self.visit(node.target)
        value = self.visit(node.value)

        if isinstance(node.op, ast.Pow):
            self.write("%s = %s ** %s" % (target, target, value))
        #elif isinstance(node.op, ast.FloorDiv):
        #    #self.write("%s = Math.floor((%s)/(%s));" % (target, target, value))
        #    self.write("%s = (%s/%s)" % (target, target, value))
        elif isinstance(node.op, ast.Div):
            if re.search(r"Numo::", target) or re.search(r"Numo::", value):
                self.write("%s = (%s)/(%s)" % (target, target, value))
            else:
                self.write("%s = (%s)/(%s).to_f" % (target, target, value))
        else:
            self.write("%s %s= %s" % (target, self.get_binary_op(node), value))

def visit_BinOp(self, node):
        if isinstance(node.op, ast.Mod) and isinstance(node.left, ast.Str):
            left = self.visit(node.left)
            # 'b=%(b)0d and c=%(c)d and d=%(d)d' => 'b=%<b>0d and c=%<c>d and d=%<d>d'
            left = re.sub(r"(.+?%)\((.+?)\)(.+?)", r"\1<\2>\3", left)
            self._dict_format = True
            right = self.visit(node.right)
            self._dict_format = False
            return "%s %% %s" % (left, right)
        left = self.visit(node.left)
        right = self.visit(node.right)

        if isinstance(node.op, ast.Pow):
            return "%s ** %s" % (left, right)
        if isinstance(node.op, ast.Div):
            if re.search(r"Numo::", left) or re.search(r"Numo::", right):
                return "(%s)/(%s)" % (left, right)
            else:
                return "(%s)/(%s).to_f" % (left, right)

        return "(%s)%s(%s)" % (left, self.get_binary_op(node), right)

def eval_expr(expr):
    import ast
    import operator as op

    op = {
        ast.Add: op.add,
        ast.Sub: op.sub,
        ast.Mult: op.mul,
        ast.Div: op.truediv,
        ast.Pow: op.pow,
        ast.BitXor: op.xor,
        ast.USub: op.neg,
    }

    def eval_(node):
        if isinstance(node, ast.Num):
            return fractions.Fraction(node.n)
        elif isinstance(node, ast.BinOp):
            return op[type(node.op)](eval_(node.left), eval_(node.right))
        elif isinstance(node, ast.UnaryOp):
            return op[type(node.op)](eval_(node.operand))
        raise TypeError(node)

    return eval_(ast.parse(str(expr), mode='eval').body)

def parse_unit(item):
    if isinstance(item, ast.Name):
        if item.id not in valid_units:
            raise InvalidTypeException("Invalid base unit", item)
        return {item.id: 1}
    elif isinstance(item, ast.Num) and item.n == 1:
        return {}
    elif not isinstance(item, ast.BinOp):
        raise InvalidTypeException("Invalid unit expression", item)
    elif isinstance(item.op, ast.Mult):
        left, right = parse_unit(item.left), parse_unit(item.right)
        return combine_units(left, right)
    elif isinstance(item.op, ast.Div):
        left, right = parse_unit(item.left), parse_unit(item.right)
        return combine_units(left, right, div=True)
    elif isinstance(item.op, ast.Pow):
        if not isinstance(item.left, ast.Name):
            raise InvalidTypeException("Can only raise a base type to an exponent", item)
        if not isinstance(item.right, ast.Num) or not isinstance(item.right.n, int) or item.right.n <= 0:
            raise InvalidTypeException("Exponent must be positive integer", item)
        return {item.left.id: item.right.n}
    else:
        raise InvalidTypeException("Invalid unit expression", item)


# Parses an expression representing a type. Annotation refers to whether
# the type is to be located in memory or storage

def doBinaryOp(op, l, r):
    """Perform the given AST binary operation on the values"""
    top = type(op)
    if top == ast.Add:
        return l + r
    elif top == ast.Sub:
        return l - r
    elif top == ast.Mult:
        return l * r
    elif top == ast.Div:
        # Don't bother if this will be a really long float- it won't work properly!
        # Also, in Python 3 this is floating division, so perform it accordingly.
        val = 1.0 * l / r
        if (val * 1e10 % 1.0) != 0:
            raise Exception("Repeating Float")
        return val
    elif top == ast.Mod:
        return l % r
    elif top == ast.Pow:
        return l ** r
    elif top == ast.LShift:
        return l << r
    elif top == ast.RShift:
        return l >> r
    elif top == ast.BitOr:
        return l | r
    elif top == ast.BitXor:
        return l ^ r
    elif top == ast.BitAnd:
        return l & r
    elif top == ast.FloorDiv:
        return l // r

def visit_AugAssign(self, node):
        if node.op.__class__ != ast.Pow:
            return node
        dummy_math = ast.Name(id="math", ctx=ast.Load())
        dummy_func = ast.Attribute(value=dummy_math, attr="pow", ctx=ast.Load())
        dummy_call = ast.Call(func=dummy_func, args=[node.target, node.value], keywords=[], starargs=None, kwargs=None)
        return ast.Assign(targets=[node.target], value=dummy_call)

def visit_BinOp(self, node):
        if node.op.__class__ != ast.Pow:
            return node
        # math.pow
        dummy_math = ast.Name(id="math", ctx=ast.Load())
        dummy_func = ast.Attribute(value=dummy_math, attr="pow", ctx=ast.Load())
        return ast.Call(func=dummy_func, args=[node.left, node.right], keywords=[], starargs=None, kwargs=None)

def visit_AugAssign(self, node):
        assert node.op.__class__ not in [ast.Pow, ast.FloorDiv]
        target = self.visit(node.target)
        op = OPERATOR_MAP[node.op.__class__]
        value = self.visit(node.value)
        return cpp.AugAssign(target, op, value)

def visit_BinOp(self, node):
        assert node.op.__class__ not in [ast.Pow, ast.FloorDiv]
        left = self.visit(node.left)
        op = OPERATOR_MAP[node.op.__class__]
        right = self.visit(node.right)
        return cpp.BinOp(left=left, op=op, right=right)

def visit_BinOp(self, node):
        if node.op.__class__ in self.operators:
            sympy_class = self.operators[node.op.__class__]
            right = self.visit(node.right)

            if isinstance(node.op, ast.Sub):
                right = ast.UnaryOp(op=ast.USub(), operand=right)
            elif isinstance(node.op, ast.Div):
                right = ast.Call(
                    func=ast.Name(id='Pow', ctx=ast.Load()),
                    args=[right, ast.UnaryOp(op=ast.USub(), operand=ast.Num(1))],
                    keywords=[ast.keyword(arg='evaluate', value=ast.Name(id='False', ctx=ast.Load()))],
                    starargs=None,
                    kwargs=None
                )

            new_node = ast.Call(
                func=ast.Name(id=sympy_class, ctx=ast.Load()),
                args=[self.visit(node.left), right],
                keywords=[ast.keyword(arg='evaluate', value=ast.Name(id='False', ctx=ast.Load()))],
                starargs=None,
                kwargs=None
            )

            if sympy_class in ('Add', 'Mul'):
                # Denest Add or Mul as appropriate
                new_node.args = self.flatten(new_node.args, sympy_class)

            return new_node
        return node

def test_pow(self):
        self.check_optimize_func("2 ** 3", "8")
        self.check_optimize_func("2.0 ** 3.0", "8.0")

        # complex
        self.check_dont_optimize_func("2.0j ** 3.0")
        self.check_dont_optimize_func("2.0 ** 3.0j")

        # 0 ** -1
        self.check_dont_optimize_func("0 ** -1",
                                 ast.BinOp(left=ast.Num(n=0), op=ast.Pow(), right=ast.Num(-1)))
        self.check_dont_optimize_func("0.0 ** -1",
                                 ast.BinOp(left=ast.Num(n=0.0), op=ast.Pow(), right=ast.Num(-1)))

def preprocess_input_python(s):
    rootnode = py_ast.get_ast(s)
    rootnode = add_str_node(rootnode)

    for node in py_ast.find_all(rootnode, ast.BinOp):
        if isinstance(node.op, ast.Pow):
            if not py_ast.is_int_constant_py_ast(py_ast.dump_ast(node.right)):
                new_str = 'pow(' + py_ast.dump_ast(node.left) + ', ' + py_ast.dump_ast(node.right) + ')'
                new_node = py_ast.get_ast(new_str).body[0].value
                py_ast.replace_node(rootnode, node, new_node)

    for node in py_ast.find_all(rootnode, ast.Call):
        if isinstance(node.func, ast.Attribute):
            if isinstance(node.func.value, ast.Name) and node.func.attr in ['floow', 'ceil']:
                if node.func.value.id == 'math':
                    py_ast.replace_node(node, node.func.value, py_ast.get_ast('numpy').body[0].value)

    ans = py_ast.dump_ast(rootnode)
    ans = 'import numpy\n' + ans

    lines = ans.split('\n')
    i = 0
    while i < len(lines):
        line = lines[i]
        if line.startswith('#'):
            j = i + 1
            while j < len(lines) and lines[j].strip() == '':
                del lines[j]
        i += 1

    ans = '\n'.join(lines)

    return ans

def get_binary_op_str(bin_op_node):
    """Returns the string representation of the binary operator node (e.g. +, -,
    etc.). For some reason astor doesn't implement this???
    """

    if isinstance(bin_op_node, ast.Add):
        return "+"

    elif isinstance(bin_op_node, ast.Sub):
        return "-"

    elif isinstance(bin_op_node, ast.Mult):
        return "*"

    elif isinstance(bin_op_node, ast.Div):
        return "/"

    elif isinstance(bin_op_node, ast.Mod):
        return "%"

    elif isinstance(bin_op_node, ast.Pow):
        return "**"

    elif isinstance(bin_op_node, ast.LShift):
        return "<<"

    elif isinstance(bin_op_node, ast.RShift):
        return ">>"

    else:
        raise ValueError("No string defined for binary operator node %s" % \
            bin_op_node.__class__.__name__)

def mutate_Mult_to_Pow(self, node):
        if self.should_mutate(node):
            return ast.Pow()
        raise MutationResign()

def pythonast(self, args, tonative=False):
        return ast.BinOp(args[0], ast.Pow(), args[1])

def BinOp_pow(t, x):
    if isinstance(x.op, ast.Pow):
        return JSCall(
            JSAttribute(
                JSName('Math'),
                'pow'),
            [x.left, x.right])

def _update(self):
        """update tkk
        """
        # we don't need to update the base TKK value when it is still valid
        now = math.floor(int(time.time() * 1000) / 3600000.0)
        if self.tkk and int(self.tkk.split('.')[0]) == now:
            return

        r = self.session.get(self.host)
        # this will be the same as python code after stripping out a reserved word 'var'
        code = unicode(self.RE_TKK.search(r.text).group(1)).replace('var ', '')
        # unescape special ascii characters such like a \x3d(=)
        if PY3:  # pragma: no cover
            code = code.encode().decode('unicode-escape')
        else:  # pragma: no cover
            code = code.decode('string_escape')

        if code:
            tree = ast.parse(code)
            visit_return = False
            operator = '+'
            n, keys = 0, dict(a=0, b=0)
            for node in ast.walk(tree):
                if isinstance(node, ast.Assign):
                    name = node.targets[0].id
                    if name in keys:
                        if isinstance(node.value, ast.Num):
                            keys[name] = node.value.n
                        # the value can sometimes be negative
                        elif isinstance(node.value, ast.UnaryOp) and \
                                isinstance(node.value.op, ast.USub):  # pragma: nocover
                            keys[name] = -node.value.operand.n
                elif isinstance(node, ast.Return):
                    # parameters should be set after this point
                    visit_return = True
                elif visit_return and isinstance(node, ast.Num):
                    n = node.n
                elif visit_return and n > 0:
                    # the default operator is '+' but implement some more for
                    # all possible scenarios
                    if isinstance(node, ast.Add):  # pragma: nocover
                        pass
                    elif isinstance(node, ast.Sub):  # pragma: nocover
                        operator = '-'
                    elif isinstance(node, ast.Mult):  # pragma: nocover
                        operator = '*'
                    elif isinstance(node, ast.Pow):  # pragma: nocover
                        operator = '**'
                    elif isinstance(node, ast.BitXor):  # pragma: nocover
                        operator = '^'
            # a safety way to avoid Exceptions
            clause = compile('{1}{0}{2}'.format(
                operator, keys['a'], keys['b']), '', 'eval')
            value = eval(clause, dict(__builtin__={}))
            result = '{}.{}'.format(n, value)

            self.tkk = result

def check_binop(self, op, left, right):
        if isinstance(left, COMPLEX_TYPES) and isinstance(right, COMPLEX_TYPES):
            if isinstance(op, DIVIDE_BINOPS) and not right:
                # x/0: ZeroDivisionError
                return False

            if isinstance(op, ast.Pow):
                if isinstance(left, complex) or isinstance(right, complex):
                    return False

                return check_pow(self.config, left, right)

            if isinstance(op, (ast.LShift, ast.RShift)) and right < 0:
                # 1 << -3 and 1 >> -3 raise a ValueError
                return False

        if isinstance(left, int) and isinstance(right, int):
            return True

        if isinstance(left, FLOAT_TYPES) and isinstance(right, FLOAT_TYPES):
            return isinstance(op, FLOAT_BINOPS)

        if isinstance(left, COMPLEX_TYPES) and isinstance(right, COMPLEX_TYPES):
            return isinstance(op, COMPLEX_BINOPS)

        if isinstance(op, ast.Mult):
            if isinstance(right, int):
                # bytes * int
                if isinstance(left, bytes):
                    return (len(left) * right <= self.config.max_bytes_len)
                # str * int
                if isinstance(left, str):
                    return (len(left) * right <= self.config.max_str_len)
                # tuple * int
                if isinstance(left, tuple):
                    size = get_constant_size(left)
                    return (size * right <= self.config.max_seq_len)

            if isinstance(left, int):
                # int * bytes
                if isinstance(right, bytes):
                    return (left * len(right) <= self.config.max_bytes_len)
                # int * str
                if isinstance(right, str):
                    return (left * len(right) <= self.config.max_str_len)
                # int * tuple
                if isinstance(right, tuple):
                    size = get_constant_size(right)
                    return (left * size <= self.config.max_seq_len)

        if isinstance(op, ast.Add):
            if isinstance(left, str) and isinstance(right, str):
                return ((len(left) + len(right)) <= self.config.max_str_len)

            if isinstance(left, bytes) and isinstance(right, bytes):
                return ((len(left) + len(right)) <= self.config.max_bytes_len)

            if isinstance(left, tuple) and isinstance(right, tuple):
                return ((len(left) + len(right)) <= self.config.max_seq_len)

        return False

def _update(self):
        """update tkk
        """
        # we don't need to update the base TKK value when it is still valid
        now = math.floor(int(time.time() * 1000) / 3600000.0)
        if self.tkk and int(self.tkk.split('.')[0]) == now:
            return

        r = self.session.get(self.host)
        # this will be the same as python code after stripping out a reserved word 'var'
        code = str(self.RE_TKK.search(r.text).group(1)).replace('var ', '')
        # unescape special ascii characters such like a \x3d(=)
        code = code.encode().decode('unicode-escape')

        if code:
            tree = ast.parse(code)
            visit_return = False
            operator = '+'
            n, keys = 0, dict(a=0, b=0)
            for node in ast.walk(tree):
                if isinstance(node, ast.Assign):
                    name = node.targets[0].id
                    if name in keys:
                        if isinstance(node.value, ast.Num):
                            keys[name] = node.value.n
                        # the value can sometimes be negative
                        elif isinstance(node.value, ast.UnaryOp) and \
                                isinstance(node.value.op, ast.USub):  # pragma: nocover
                            keys[name] = -node.value.operand.n
                elif isinstance(node, ast.Return):
                    # parameters should be set after this point
                    visit_return = True
                elif visit_return and isinstance(node, ast.Num):
                    n = node.n
                elif visit_return and n > 0:
                    # the default operator is '+' but implement some more for
                    # all possible scenarios
                    if isinstance(node, ast.Add):  # pragma: nocover
                        pass
                    elif isinstance(node, ast.Sub):  # pragma: nocover
                        operator = '-'
                    elif isinstance(node, ast.Mult):  # pragma: nocover
                        operator = '*'
                    elif isinstance(node, ast.Pow):  # pragma: nocover
                        operator = '**'
                    elif isinstance(node, ast.BitXor):  # pragma: nocover
                        operator = '^'
            # a safety way to avoid Exceptions
            clause = compile('{1}{0}{2}'.format(
                operator, keys['a'], keys['b']), '', 'eval')
            value = eval(clause, dict(__builtin__={}))
            result = '{}.{}'.format(n, value)

            self.tkk = result

def visit_BinOp(self, node):
        if node.op.__class__ in self.operators:
            sympy_class = self.operators[node.op.__class__]
            right = self.visit(node.right)
            left = self.visit(node.left)
            if isinstance(node.left, ast.UnaryOp) and (isinstance(node.right, ast.UnaryOp) == 0) and sympy_class in ('Mul',):
                left, right = right, left
            if isinstance(node.op, ast.Sub):
                right = ast.UnaryOp(op=ast.USub(), operand=right)
            if isinstance(node.op, ast.Div):
                if isinstance(node.left, ast.UnaryOp):
                    if isinstance(node.right,ast.UnaryOp):
                        left, right = right, left
                    left = ast.Call(
                    func=ast.Name(id='Pow', ctx=ast.Load()),
                    args=[left, ast.UnaryOp(op=ast.USub(), operand=ast.Num(1))],
                    keywords=[ast.keyword(arg='evaluate', value=ast.Name(id='False', ctx=ast.Load()))],
                    starargs=None,
                    kwargs=None
                )
                else:
                    right = ast.Call(
                    func=ast.Name(id='Pow', ctx=ast.Load()),
                    args=[right, ast.UnaryOp(op=ast.USub(), operand=ast.Num(1))],
                    keywords=[ast.keyword(arg='evaluate', value=ast.Name(id='False', ctx=ast.Load()))],
                    starargs=None,
                    kwargs=None
                )

            new_node = ast.Call(
                func=ast.Name(id=sympy_class, ctx=ast.Load()),
                args=[left, right],
                keywords=[ast.keyword(arg='evaluate', value=ast.Name(id='False', ctx=ast.Load()))],
                starargs=None,
                kwargs=None
            )

            if sympy_class in ('Add', 'Mul'):
                # Denest Add or Mul as appropriate
                new_node.args = self.flatten(new_node.args, sympy_class)

            return new_node
        return node

def _aslimit(value, lc):
        if isinstance(value, string_types):
            module = ast.parse(value)
            if isinstance(module, ast.Module) and len(module.body) == 1 and isinstance(module.body[0], ast.Expr):
                def restrictedeval(expr):
                    if isinstance(expr, ast.Num):
                        return expr.n

                    elif isinstance(expr, ast.Name) and expr.id == "inf":
                        return femtocode.typesystem.inf

                    elif isinstance(expr, ast.Name) and expr.id == "pi":
                        return math.pi

                    elif isinstance(expr, ast.UnaryOp) and isinstance(expr.op, ast.USub):
                        return -restrictedeval(expr.operand)

                    elif isinstance(expr, ast.BinOp) and isinstance(expr.op, ast.Add):
                        return restrictedeval(expr.left) + restrictedeval(expr.right)

                    elif isinstance(expr, ast.BinOp) and isinstance(expr.op, ast.Sub):
                        return restrictedeval(expr.left) - restrictedeval(expr.right)

                    elif isinstance(expr, ast.BinOp) and isinstance(expr.op, ast.Mult):
                        return restrictedeval(expr.left) * restrictedeval(expr.right)

                    elif isinstance(expr, ast.BinOp) and isinstance(expr.op, ast.Div):
                        return restrictedeval(expr.left) / restrictedeval(expr.right)

                    elif isinstance(expr, ast.BinOp) and isinstance(expr.op, ast.Pow):
                        return restrictedeval(expr.left) ** restrictedeval(expr.right)

                    elif isinstance(expr, ast.Call) and isinstance(expr.func, ast.Name) and expr.func.id == "almost" and len(expr.args) == 1 and len(expr.keywords) == 0 and expr.kwargs is None and expr.starargs is None:
                        return femtocode.typesystem.almost(restrictedeval(expr.args[0]))

                    else:
                        raise DatasetDeclaration.Error(lc, "couldn't parse as a min/max/least/most limit: {0}".format(value))

                return restrictedeval(module.body[0].value)

        elif isinstance(value, (int, long, float)):
            return value

        elif isinstance(value, femtocode.typesystem.almost) and isinstance(value.real, (int, long, float)):
            return value

        else:
            raise DatasetDeclaration.Error(lc, "unrecognized type for min/max/least/most limit: {0}".format(value))