variable 切片, 不能用不能用numpy数组的元素当成索引值，只能用python原生的list?
Created by: zylustc
paddle: 1.8.3 示例程序：
import paddle.fluid as fluid
import numpy as np
with fluid.dygraph.guard():
value = np.arange(140).reshape(10,14).astype("float64")
a=fluid.dygraph.to_variable(value)
a.stop_gradient=False
linear1 = fluid.Linear(14, 5, dtype="float64")
linear2 = fluid.Linear(5, 1, dtype="float64")
adam = fluid.optimizer.Adam(parameter_list=[linear1.parameters(),linear2.parameters()])
nl=[0,2,5,10]
nl=np.array(nl,dtype=np.int32)
out=fluid.dygraph.to_variable(np.zeros(1,dtype=np.float64))
for i in range(3):
x=a[nl[i]:nl[i+1]]
x=linear1(x)
x=linear2(x)
out+=fluid.layers.reduce_sum(x,dim=0)
out.backward()报错：
Traceback (most recent call last):
File "33.py", line 16, in <module>
x=a[nl[i]:nl[i+1]]
paddle.fluid.core_avx.EnforceNotMet:
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C++ Call Stacks (More useful to developers):
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0 std::string paddle::platform::GetTraceBackString<std::string const&>(std::string const&, char const*, int)
1 paddle::platform::EnforceNotMet::EnforceNotMet(std::string const&, char const*, int)
2 paddle::operators::SliceOp::InferShape(paddle::framework::InferShapeContext*) const
3 paddle::imperative::PreparedOp::Run(std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::unordered_map<std::string, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>, std::hash<std::string>, std::equal_to<std::string>, std::allocator<std::pair<std::string const, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> > > > const&)
4 paddle::imperative::OpBase::Run(paddle::framework::OperatorBase const&, std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::unordered_map<std::string, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>, std::hash<std::string>, std::equal_to<std::string>, std::allocator<std::pair<std::string const, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> > > > const&, paddle::platform::Place const&)
5 paddle::imperative::Tracer::TraceOp(std::string const&, std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::unordered_map<std::string, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>, std::hash<std::string>, std::equal_to<std::string>, std::allocator<std::pair<std::string const, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> > > >, paddle::platform::Place const&, bool)
6 paddle::imperative::Tracer::TraceOp(std::string const&, std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::map<std::string, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > >, std::less<std::string>, std::allocator<std::pair<std::string const, std::vector<std::shared_ptr<paddle::imperative::VarBase>, std::allocator<std::shared_ptr<paddle::imperative::VarBase> > > > > > const&, std::unordered_map<std::string, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_>, std::hash<std::string>, std::equal_to<std::string>, std::allocator<std::pair<std::string const, boost::variant<boost::blank, int, float, std::string, std::vector<int, std::allocator<int> >, std::vector<float, std::allocator<float> >, std::vector<std::string, std::allocator<std::string> >, bool, std::vector<bool, std::allocator<bool> >, paddle::framework::BlockDesc*, long, std::vector<paddle::framework::BlockDesc*, std::allocator<paddle::framework::BlockDesc*> >, std::vector<long, std::allocator<long> >, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_, boost::detail::variant::void_> > > >)
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Error Message Summary:
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Error: end should greater than start
[Hint: Expected end > start, but received end:0 <= start:0.] at (/paddle/paddle/fluid/operators/slice_op.cc:115)如果不把nl数组转成numpy的数组，使用python原生的list就没有问题，使用numpy数组就会报错