the module name is right,but it still failed with boost::python::error_already_set

[lemonaha]

I0605 20:26:05.052970 10307 layer_factory.hpp:77] Creating layer triplet_select
I0605 20:26:05.668673 10307 net.cpp:84] Creating Layer triplet_select
I0605 20:26:05.668705 10307 net.cpp:406] triplet_select <- pool10
I0605 20:26:05.668715 10307 net.cpp:406] triplet_select <- label
I0605 20:26:05.668722 10307 net.cpp:380] triplet_select -> archor
I0605 20:26:05.668730 10307 net.cpp:380] triplet_select -> positive
I0605 20:26:05.668736 10307 net.cpp:380] triplet_select -> negative
I0605 20:26:05.668946 10307 net.cpp:122] Setting up triplet_select
I0605 20:26:05.668963 10307 net.cpp:129] Top shape: 10 34 (340)
I0605 20:26:05.668968 10307 net.cpp:129] Top shape: 10 34 (340)
I0605 20:26:05.668972 10307 net.cpp:129] Top shape: 10 34 (340)
I0605 20:26:05.668975 10307 net.cpp:137] Memory required for data: 80587760
I0605 20:26:05.668980 10307 layer_factory.hpp:77] Creating layer tripletloss
I0605 20:26:05.669806 10307 net.cpp:84] Creating Layer tripletloss
I0605 20:26:05.669819 10307 net.cpp:406] tripletloss <- archor
I0605 20:26:05.669824 10307 net.cpp:406] tripletloss <- positive
I0605 20:26:05.669828 10307 net.cpp:406] tripletloss <- negative
I0605 20:26:05.669833 10307 net.cpp:380] tripletloss -> loss
terminate called after throwing an instance of 'boost::python::error_already_set'
*** Aborted at 1496665565 (unix time) try "date -d @1496665565" if you are using GNU date ***
PC: @     0x7f1c49afec37 (unknown)

and I didn't change the code below:

#add activation layer may increase the feature's expression
layer {
  name: "triplet_select"
  type: "Python"
  bottom: "fc9_1"
  bottom: "labels"
  top: "archor"
  top: "positive"
  top: "negative"
  python_param {
    module: "tripletselectlayer"
    layer: "TripletSelectLayer"
  }
}
layer {
  name: "tripletloss"
  type: "Python"
  bottom: "archor"
  bottom: "positive"
  bottom: "negative"
  top: "loss"
  python_param {
    module: "tripletlosslayer"
    layer: "TripletLayer"
    param_str: "'margin': 0.2"
  }
  loss_weight: 1
}