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))
python类comprehension()的实例源码
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_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_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 _check_comprehension(self, fac):
self.expr(fac([]), "comprehension with no generators")
g = ast.comprehension(ast.Name("x", ast.Load()),
ast.Name("x", ast.Load()), [])
self.expr(fac([g]), "must have Store context")
g = ast.comprehension(ast.Name("x", ast.Store()),
ast.Name("x", ast.Store()), [])
self.expr(fac([g]), "must have Load context")
x = ast.Name("x", ast.Store())
y = ast.Name("y", ast.Load())
g = ast.comprehension(x, y, [None])
self.expr(fac([g]), "None disallowed")
g = ast.comprehension(x, y, [ast.Name("x", ast.Store())])
self.expr(fac([g]), "must have Load context")
def _simple_comp(self, fac):
g = ast.comprehension(ast.Name("x", ast.Store()),
ast.Name("x", ast.Load()), [])
self.expr(fac(ast.Name("x", ast.Store()), [g]),
"must have Load context")
def wrap(gens):
return fac(ast.Name("x", ast.Store()), gens)
self._check_comprehension(wrap)
def test_dictcomp(self):
g = ast.comprehension(ast.Name("y", ast.Store()),
ast.Name("p", ast.Load()), [])
c = ast.DictComp(ast.Name("x", ast.Store()),
ast.Name("y", ast.Load()), [g])
self.expr(c, "must have Load context")
c = ast.DictComp(ast.Name("x", ast.Load()),
ast.Name("y", ast.Store()), [g])
self.expr(c, "must have Load context")
def factory(comps):
k = ast.Name("x", ast.Load())
v = ast.Name("y", ast.Load())
return ast.DictComp(k, v, comps)
self._check_comprehension(factory)
def visit_Call(self, node):
if node.func.id not in GRP_FUNCS:
return node
else:
self.generic_visit(node)
return ast.Call(
func=node.func,
args=[
ast.ListComp(
elt=node.args[0],
generators=[
ast.comprehension(
target=ast.Name(id="datarow", ctx=ast.Store(), lineno=0, col_offset=0),
iter=ast.Name(id="data", ctx=ast.Load(), lineno=0, col_offset=0),
ifs=[],
lineno=0,
col_offset=0
)
],
lineno=0,
col_offset=0,
)
],
keywords=[],
ctx=ast.Load(),
lineno=0,
col_offset=0,
)
def addBinding(self, node, value):
"""
Called when a binding is altered.
- `node` is the statement responsible for the change
- `value` is the new value, a Binding instance
"""
# assert value.source in (node, node.parent):
for scope in self.scopeStack[::-1]:
if value.name in scope:
break
existing = scope.get(value.name)
if existing and not self.differentForks(node, existing.source):
parent_stmt = self.getParent(value.source)
if isinstance(existing, Importation) and isinstance(parent_stmt, ast.For):
self.report(messages.ImportShadowedByLoopVar,
node, value.name, existing.source)
elif scope is self.scope:
if (isinstance(parent_stmt, ast.comprehension) and
not isinstance(self.getParent(existing.source),
(ast.For, ast.comprehension))):
self.report(messages.RedefinedInListComp,
node, value.name, existing.source)
elif not existing.used and value.redefines(existing):
self.report(messages.RedefinedWhileUnused,
node, value.name, existing.source)
elif isinstance(existing, Importation) and value.redefines(existing):
existing.redefined.append(node)
if value.name in self.scope:
# then assume the rebound name is used as a global or within a loop
value.used = self.scope[value.name].used
self.scope[value.name] = value
def handleNodeStore(self, node):
name = getNodeName(node)
if not name:
return
# if the name hasn't already been defined in the current scope
if isinstance(self.scope, FunctionScope) and name not in self.scope:
# for each function or module scope above us
for scope in self.scopeStack[:-1]:
if not isinstance(scope, (FunctionScope, ModuleScope)):
continue
# if the name was defined in that scope, and the name has
# been accessed already in the current scope, and hasn't
# been declared global
used = name in scope and scope[name].used
if used and used[0] is self.scope and name not in self.scope.globals:
# then it's probably a mistake
self.report(messages.UndefinedLocal,
scope[name].used[1], name, scope[name].source)
break
parent_stmt = self.getParent(node)
if isinstance(parent_stmt, (ast.For, ast.comprehension)) or (
parent_stmt != node.parent and
not self.isLiteralTupleUnpacking(parent_stmt)):
binding = Binding(name, node)
elif name == '__all__' and isinstance(self.scope, ModuleScope):
binding = ExportBinding(name, node.parent, self.scope)
else:
binding = Assignment(name, node)
self.addBinding(node, binding)
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_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 _check_comprehension(self, fac):
self.expr(fac([]), "comprehension with no generators")
g = ast.comprehension(ast.Name("x", ast.Load()),
ast.Name("x", ast.Load()), [])
self.expr(fac([g]), "must have Store context")
g = ast.comprehension(ast.Name("x", ast.Store()),
ast.Name("x", ast.Store()), [])
self.expr(fac([g]), "must have Load context")
x = ast.Name("x", ast.Store())
y = ast.Name("y", ast.Load())
g = ast.comprehension(x, y, [None])
self.expr(fac([g]), "None disallowed")
g = ast.comprehension(x, y, [ast.Name("x", ast.Store())])
self.expr(fac([g]), "must have Load context")
def _simple_comp(self, fac):
g = ast.comprehension(ast.Name("x", ast.Store()),
ast.Name("x", ast.Load()), [])
self.expr(fac(ast.Name("x", ast.Store()), [g]),
"must have Load context")
def wrap(gens):
return fac(ast.Name("x", ast.Store()), gens)
self._check_comprehension(wrap)
def test_dictcomp(self):
g = ast.comprehension(ast.Name("y", ast.Store()),
ast.Name("p", ast.Load()), [])
c = ast.DictComp(ast.Name("x", ast.Store()),
ast.Name("y", ast.Load()), [g])
self.expr(c, "must have Load context")
c = ast.DictComp(ast.Name("x", ast.Load()),
ast.Name("y", ast.Store()), [g])
self.expr(c, "must have Load context")
def factory(comps):
k = ast.Name("x", ast.Load())
v = ast.Name("y", ast.Load())
return ast.DictComp(k, v, comps)
self._check_comprehension(factory)
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 addBinding(self, node, value):
"""
Called when a binding is altered.
- `node` is the statement responsible for the change
- `value` is the new value, a Binding instance
"""
# assert value.source in (node, node.parent):
for scope in self.scopeStack[::-1]:
if value.name in scope:
break
existing = scope.get(value.name)
if existing and not self.differentForks(node, existing.source):
parent_stmt = self.getParent(value.source)
if isinstance(existing, Importation) and isinstance(parent_stmt, ast.For):
self.report(messages.ImportShadowedByLoopVar,
node, value.name, existing.source)
elif scope is self.scope:
if (isinstance(parent_stmt, ast.comprehension) and
not isinstance(self.getParent(existing.source),
(ast.For, ast.comprehension))):
self.report(messages.RedefinedInListComp,
node, value.name, existing.source)
elif not existing.used and value.redefines(existing):
self.report(messages.RedefinedWhileUnused,
node, value.name, existing.source)
elif isinstance(existing, Importation) and value.redefines(existing):
existing.redefined.append(node)
if value.name in self.scope:
# then assume the rebound name is used as a global or within a loop
value.used = self.scope[value.name].used
self.scope[value.name] = value
def handleNodeStore(self, node):
name = getNodeName(node)
if not name:
return
# if the name hasn't already been defined in the current scope
if isinstance(self.scope, FunctionScope) and name not in self.scope:
# for each function or module scope above us
for scope in self.scopeStack[:-1]:
if not isinstance(scope, (FunctionScope, ModuleScope)):
continue
# if the name was defined in that scope, and the name has
# been accessed already in the current scope, and hasn't
# been declared global
used = name in scope and scope[name].used
if used and used[0] is self.scope and name not in self.scope.globals:
# then it's probably a mistake
self.report(messages.UndefinedLocal,
scope[name].used[1], name, scope[name].source)
break
parent_stmt = self.getParent(node)
if isinstance(parent_stmt, (ast.For, ast.comprehension)) or (
parent_stmt != node.parent and
not self.isLiteralTupleUnpacking(parent_stmt)):
binding = Binding(name, node)
elif name == '__all__' and isinstance(self.scope, ModuleScope):
binding = ExportBinding(name, node.parent, self.scope)
else:
binding = Assignment(name, node)
self.addBinding(node, binding)
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 _check_comprehension(self, fac):
self.expr(fac([]), "comprehension with no generators")
g = ast.comprehension(ast.Name("x", ast.Load()),
ast.Name("x", ast.Load()), [])
self.expr(fac([g]), "must have Store context")
g = ast.comprehension(ast.Name("x", ast.Store()),
ast.Name("x", ast.Store()), [])
self.expr(fac([g]), "must have Load context")
x = ast.Name("x", ast.Store())
y = ast.Name("y", ast.Load())
g = ast.comprehension(x, y, [None])
self.expr(fac([g]), "None disallowed")
g = ast.comprehension(x, y, [ast.Name("x", ast.Store())])
self.expr(fac([g]), "must have Load context")
def _simple_comp(self, fac):
g = ast.comprehension(ast.Name("x", ast.Store()),
ast.Name("x", ast.Load()), [])
self.expr(fac(ast.Name("x", ast.Store()), [g]),
"must have Load context")
def wrap(gens):
return fac(ast.Name("x", ast.Store()), gens)
self._check_comprehension(wrap)
def test_dictcomp(self):
g = ast.comprehension(ast.Name("y", ast.Store()),
ast.Name("p", ast.Load()), [])
c = ast.DictComp(ast.Name("x", ast.Store()),
ast.Name("y", ast.Load()), [g])
self.expr(c, "must have Load context")
c = ast.DictComp(ast.Name("x", ast.Load()),
ast.Name("y", ast.Store()), [g])
self.expr(c, "must have Load context")
def factory(comps):
k = ast.Name("x", ast.Load())
v = ast.Name("y", ast.Load())
return ast.DictComp(k, v, comps)
self._check_comprehension(factory)
def addBinding(self, node, value):
"""
Called when a binding is altered.
- `node` is the statement responsible for the change
- `value` is the new value, a Binding instance
"""
# assert value.source in (node, node.parent):
for scope in self.scopeStack[::-1]:
if value.name in scope:
break
existing = scope.get(value.name)
if existing and not self.differentForks(node, existing.source):
parent_stmt = self.getParent(value.source)
if isinstance(existing, Importation) and isinstance(parent_stmt, ast.For):
self.report(messages.ImportShadowedByLoopVar,
node, value.name, existing.source)
elif scope is self.scope:
if (isinstance(parent_stmt, ast.comprehension) and
not isinstance(self.getParent(existing.source),
(ast.For, ast.comprehension))):
self.report(messages.RedefinedInListComp,
node, value.name, existing.source)
elif not existing.used and value.redefines(existing):
self.report(messages.RedefinedWhileUnused,
node, value.name, existing.source)
elif isinstance(existing, Importation) and value.redefines(existing):
existing.redefined.append(node)
if value.name in self.scope:
# then assume the rebound name is used as a global or within a loop
value.used = self.scope[value.name].used
self.scope[value.name] = value
def handleNodeStore(self, node):
name = getNodeName(node)
if not name:
return
# if the name hasn't already been defined in the current scope
if isinstance(self.scope, FunctionScope) and name not in self.scope:
# for each function or module scope above us
for scope in self.scopeStack[:-1]:
if not isinstance(scope, (FunctionScope, ModuleScope)):
continue
# if the name was defined in that scope, and the name has
# been accessed already in the current scope, and hasn't
# been declared global
used = name in scope and scope[name].used
if used and used[0] is self.scope and name not in self.scope.globals:
# then it's probably a mistake
self.report(messages.UndefinedLocal,
scope[name].used[1], name, scope[name].source)
break
parent_stmt = self.getParent(node)
if isinstance(parent_stmt, (ast.For, ast.comprehension)) or (
parent_stmt != node.parent and
not self.isLiteralTupleUnpacking(parent_stmt)):
binding = Binding(name, node)
elif name == '__all__' and isinstance(self.scope, ModuleScope):
binding = ExportBinding(name, node.parent, self.scope)
else:
binding = Assignment(name, node)
self.addBinding(node, binding)
def _peval_comprehension_generators(state, generators, ctx):
if len(generators) == 0:
return state, []
generator = generators[0]
next_generators = generators[1:]
state, iter_result = _peval_expression(state, generator.iter, ctx)
masked_bindings = _get_masked_bindings(generator.target, ctx.bindings)
masked_ctx = ctx.set('bindings', masked_bindings)
state, ifs_result = _peval_comprehension_ifs(state, generator.ifs, masked_ctx)
if is_known_value(ifs_result):
success, bool_value = try_call(bool, args=(ifs_result.value,))
if success and bool_value:
ifs_result = []
state, new_generator_kwds = map_reify(
state, dict(target=generator.target, iter=iter_result, ifs=ifs_result))
new_generator = ast.comprehension(**new_generator_kwds)
state, new_generators = _peval_comprehension_generators(state, next_generators, ctx)
return state, [new_generator] + new_generators
def _visit_For(self, node):
if not isinstance(node.target, ast.Name):
return
# for i in (1, 2, 3): ...
if not isinstance(node.iter, ast.Constant):
return
iter_value = node.iter.value
if not isinstance(iter_value, tuple):
return
if not(1 <= len(iter_value) <= self.config.unroll_loops):
return
# don't optimize if 'break' or 'continue' is found in the loop body
found = None
def find_callback(node):
nonlocal found
found = node
return False
# FIXME: restrict this the current scope
# (don't enter class/function def/list comprehension/...)
visitor = FindNodes(CANNOT_UNROLL, find_callback)
visitor.visit(node)
if found is not None:
self.log(node,
"cannot unroll loop: %s is used at line %s",
compact_dump(found),
found.lineno)
return
name = node.target.id
body = node.body
# replace 'for i in (1, 2, 3): body' with...
new_node = []
for value in node.iter.value:
value_ast = self.new_constant(node.iter, value)
if value_ast is None:
return
# 'i = 1'
name_ast = ast.Name(id=name, ctx=ast.Store())
copy_lineno(node, name_ast)
assign = ast.Assign(targets=[name_ast],
value=value_ast)
copy_lineno(node, assign)
new_node.append(assign)
# duplicate 'body'
new_node.extend(body)
if node.orelse:
new_node.extend(node.orelse)
self.log(node, "unroll loop (%s iterations)", len(node.iter.value))
return new_node
