def test_copy_location(self):
src = ast.parse('1 + 1', mode='eval')
src.body.right = ast.copy_location(ast.Num(2), src.body.right)
self.assertEqual(ast.dump(src, include_attributes=True),
'Expression(body=BinOp(left=Num(n=1, lineno=1, col_offset=0), '
'op=Add(), right=Num(n=2, lineno=1, col_offset=4), lineno=1, '
'col_offset=0))'
)
python类Expression()的实例源码
def test_module(self):
m = ast.Interactive([ast.Expr(ast.Name("x", ast.Store()))])
self.mod(m, "must have Load context", "single")
m = ast.Expression(ast.Name("x", ast.Store()))
self.mod(m, "must have Load context", "eval")
def SoS_exec(script, _dict=None, return_result=False):
'''Execute a statement.'''
if _dict is None:
_dict = env.sos_dict._dict
if not return_result:
exec(script, _dict)
return None
try:
stmts = list(ast.iter_child_nodes(ast.parse(script)))
if not stmts:
return
if isinstance(stmts[-1], ast.Expr):
# the last one is an expression and we will try to return the results
# so we first execute the previous statements
if len(stmts) > 1:
exec(compile(ast.Module(body=stmts[:-1]), filename="<ast>", mode="exec"), _dict)
# then we eval the last one
res = eval(compile(ast.Expression(body=stmts[-1].value), filename="<ast>", mode="eval"), _dict)
else:
# otherwise we just execute the entire code
exec(script, _dict)
res = None
except SyntaxError as e:
raise SyntaxError(f"Invalid code {script}: {e}")
#if check_readonly:
# env.sos_dict.check_readonly_vars()
return res
#
# dynamic expression that cannot be resolved during parsing
# at prepare mode etc, and has to be resolved at run time.
#
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast.parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (ast.Add, ast.Sub)) and \
isinstance(node.right, ast.Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, ast.Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, ast.Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast_parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (Add, Sub)) and \
isinstance(node.right, Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast_parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (Add, Sub)) and \
isinstance(node.right, Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast_parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (Add, Sub)) and \
isinstance(node.right, Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast_parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (Add, Sub)) and \
isinstance(node.right, Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
def make_grp_list_func(expr_str, field_names_dict, global_names_dict=None, filename=None):
"""
>>> func = make_grp_list_func('sum(a)/cnt()', {'a': 0})
>>> func([(1,), (2,), (3,)])
2
>>> func = make_grp_list_func('1+sum(a)+sum(b**2)', {'a':0, 'b':1})
>>> func([(10, 1), (20, 2)])
36
>>> func = make_grp_list_func('b+sum(a)/sum(c)', {'a': 0, 'c': 1}, {'b': 0})
>>> func([(10, 1), (20, 2), (30, 3)], [1])
11
>>> func = make_grp_list_func('sum(a)', {'a': 0})
>>> func([(1,), (2,), (3,)])
6
"""
filename = filename or '<generated>'
list_name = 'data'
lambda_args = [ast.Name(id=list_name, ctx=ast.Param(), lineno=0, col_offset=0)]
tree = ast.parse(expr_str, filename, 'eval')
tree = RewriteCntFuncs().visit(tree)
tree = RewriteGrpFuncs(field_names_dict).visit(tree)
if global_names_dict:
lambda_args.append(ast.Name(id='globaldata', ctx=ast.Param(), lineno=0, col_offset=0))
tree = RewriteName('globaldata', global_names_dict).visit(tree)
tree = ast.Expression(
body = ast.Lambda(
body=tree.body,
args=ast.arguments(
args=lambda_args,
vararg=None,
kwarg=None,
defaults=[],
),
lineno=0,
col_offset=0,
),
)
#print ast.dump(tree)
code = compile(tree, filename, 'eval')
func = eval(code)
return func
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast_parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (Add, Sub)) and \
isinstance(node.right, Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
def seteval(str_, get=None, stemmer=None, target=None):
"""Evaluate a set operation string, where each Name is fetched
Parameters
----------
str_ : str
The query to evaluate
get : function, optional
A getting method, defaults to instatiating one from _requests
stemmer : function, optional
A method to stem a query Name. If None, defaults to passthrough.
target : str, optional
A subcontext to query against. If None, defaults to text-search.
"""
if get is None:
import redbiom
config = redbiom.get_config()
get = redbiom._requests.make_get(config)
if stemmer is None:
stemmer = passthrough
if target is None:
target = 'text-search'
# Load is subject to indirection to simplify testing
globals()['Load'] = make_Load(get)
# this seems right now to be the easiest way to inject parameters
# into Name
globals()['stemmer'] = stemmer
globals()['target'] = target
formed = ast.parse(str_, mode='eval')
node_types = (ast.BitAnd, ast.BitOr, ast.BitXor, ast.Name, ast.Sub,
ast.Expression, ast.BinOp, ast.Load)
for node in ast.walk(formed):
if not isinstance(node, node_types):
raise TypeError("Unsupported node type: %s" % ast.dump(node))
result = eval(ast.dump(formed))
# clean up
global Load
del Load
del stemmer
del target
return result
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast_parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (Add, Sub)) and \
isinstance(node.right, Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
def Exec(self, source):
self.execution_count += 1
try:
nodes = ast.parse(source, self.filename)
except IndentationError as e:
raise ParseError(e)
except (OverflowError, SyntaxError, ValueError,
TypeError, MemoryError) as e:
raise ParseError(e)
stdout = StringIO.StringIO()
stderr = StringIO.StringIO()
prev_stdout = sys.stdout
prev_stderr = sys.stderr
sys.stdout = stdout
sys.stderr = stderr
try:
if isinstance(nodes.body[-1], ast.Expr):
exec_nodes = nodes.body[:-1]
interactive_nodes = nodes.body[-1:]
else:
exec_nodes, interactive_nodes = nodes.body, []
for node in exec_nodes:
mod = ast.Module([node])
code = compile(mod, self.filename, "exec")
exec(code, self.global_context, self.local_context)
result = None
for node in interactive_nodes:
source = codegen.to_source(node)
new_node = ast.parse(source, self.filename, mode="eval")
mod = ast.Expression(new_node.body)
code = compile(mod, self.filename, "eval")
result = eval(code, self.global_context, self.local_context)
sys.stdout = prev_stdout
sys.stderr = prev_stderr
return stdout.getvalue(), stderr.getvalue(), result
except Exception as e:
raise ExecError(stdout.getvalue(), stderr.getvalue(), e)
finally:
sys.stdout = prev_stdout
sys.stderr = prev_stderr
def _gclient_eval(node_or_string, global_scope, filename='<unknown>'):
"""Safely evaluates a single expression. Returns the result."""
_allowed_names = {'None': None, 'True': True, 'False': False}
if isinstance(node_or_string, basestring):
node_or_string = ast.parse(node_or_string, filename=filename, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return collections.OrderedDict(
(_convert(k), _convert(v))
for k, v in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id not in _allowed_names:
raise ValueError(
'invalid name %r (file %r, line %s)' % (
node.id, filename, getattr(node, 'lineno', '<unknown>')))
return _allowed_names[node.id]
elif isinstance(node, ast.Call):
if not isinstance(node.func, ast.Name):
raise ValueError(
'invalid call: func should be a name (file %r, line %s)' % (
filename, getattr(node, 'lineno', '<unknown>')))
if node.keywords or node.starargs or node.kwargs:
raise ValueError(
'invalid call: use only regular args (file %r, line %s)' % (
filename, getattr(node, 'lineno', '<unknown>')))
args = map(_convert, node.args)
return global_scope[node.func.id](*args)
elif isinstance(node, ast.BinOp) and isinstance(node.op, ast.Add):
return _convert(node.left) + _convert(node.right)
elif isinstance(node, ast.BinOp) and isinstance(node.op, ast.Mod):
return _convert(node.left) % _convert(node.right)
else:
raise ValueError(
'unexpected AST node: %s %s (file %r, line %s)' % (
node, ast.dump(node), filename,
getattr(node, 'lineno', '<unknown>')))
return _convert(node_or_string)
def Exec(content, global_scope, local_scope, filename='<unknown>'):
"""Safely execs a set of assignments. Mutates |local_scope|."""
node_or_string = ast.parse(content, filename=filename, mode='exec')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _visit_in_module(node):
if isinstance(node, ast.Assign):
if len(node.targets) != 1:
raise ValueError(
'invalid assignment: use exactly one target (file %r, line %s)' % (
filename, getattr(node, 'lineno', '<unknown>')))
target = node.targets[0]
if not isinstance(target, ast.Name):
raise ValueError(
'invalid assignment: target should be a name (file %r, line %s)' % (
filename, getattr(node, 'lineno', '<unknown>')))
value = _gclient_eval(node.value, global_scope, filename=filename)
if target.id in local_scope:
raise ValueError(
'invalid assignment: overrides var %r (file %r, line %s)' % (
target.id, filename, getattr(node, 'lineno', '<unknown>')))
local_scope[target.id] = value
else:
raise ValueError(
'unexpected AST node: %s %s (file %r, line %s)' % (
node, ast.dump(node), filename,
getattr(node, 'lineno', '<unknown>')))
if isinstance(node_or_string, ast.Module):
for stmt in node_or_string.body:
_visit_in_module(stmt)
else:
raise ValueError(
'unexpected AST node: %s %s (file %r, line %s)' % (
node_or_string,
ast.dump(node_or_string),
filename,
getattr(node_or_string, 'lineno', '<unknown>')))
_GCLIENT_SCHEMA.validate(local_scope)
def safe_eval(node_or_string, env):
"""
Safely evaluate an expression node or a string containing a Python
expression. The string or node provided may only consist of the following
Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
and None.
"""
_safe_names = {'None': None, 'True': True, 'False': False}
_safe_names.update(env)
if isinstance(node_or_string, basestring):
node_or_string = ast_parse(node_or_string, mode='eval')
if isinstance(node_or_string, ast.Expression):
node_or_string = node_or_string.body
def _convert(node):
if isinstance(node, ast.Str):
return node.s
elif isinstance(node, ast.Num):
return node.n
elif isinstance(node, ast.Tuple):
return tuple(map(_convert, node.elts))
elif isinstance(node, ast.List):
return list(map(_convert, node.elts))
elif isinstance(node, ast.Dict):
return dict((_convert(k), _convert(v)) for k, v
in zip(node.keys, node.values))
elif isinstance(node, ast.Name):
if node.id in _safe_names:
return _safe_names[node.id]
elif isinstance(node, ast.BinOp) and \
isinstance(node.op, (Add, Sub)) and \
isinstance(node.right, Num) and \
isinstance(node.right.n, complex) and \
isinstance(node.left, Num) and \
isinstance(node.left.n, (int, long, float)):
left = node.left.n
right = node.right.n
if isinstance(node.op, Add):
return left + right
else:
return left - right
raise ValueError('malformed string')
return _convert(node_or_string)
