Adding python callback during training

python/fasttext_module/fasttext/FastText.py

@@ -516,6 +516,7 @@ def train_supervised(*kargs, **kwargs):
         'model': "supervised"
     })
 
+    callback = kwargs.pop("callback", None)
     arg_names = ['input', 'lr', 'dim', 'ws', 'epoch', 'minCount',
                  'minCountLabel', 'minn', 'maxn', 'neg', 'wordNgrams', 'loss', 'bucket',
                  'thread', 'lrUpdateRate', 't', 'label', 'verbose', 'pretrainedVectors',
@@ -525,7 +526,10 @@ def train_supervised(*kargs, **kwargs):
                                         supervised_default)
     a = _build_args(args, manually_set_args)
     ft = _FastText(args=a)
-    fasttext.train(ft.f, a)
+    if callback:
+        fasttext.train_with_callback(ft.f, a, callback)
+    else:
+        fasttext.train(ft.f, a)
     ft.set_args(ft.f.getArgs())
     return ft
 
@@ -544,13 +548,18 @@ def train_unsupervised(*kargs, **kwargs):
     dataset pulled by the example script word-vector-example.sh, which is
     part of the fastText repository.
     """
+    callback = kwargs.pop("callback", None)
     arg_names = ['input', 'model', 'lr', 'dim', 'ws', 'epoch', 'minCount',
                  'minCountLabel', 'minn', 'maxn', 'neg', 'wordNgrams', 'loss', 'bucket',
                  'thread', 'lrUpdateRate', 't', 'label', 'verbose', 'pretrainedVectors']
     args, manually_set_args = read_args(kargs, kwargs, arg_names,
                                         unsupervised_default)
     a = _build_args(args, manually_set_args)
     ft = _FastText(args=a)
+    if callback:
+        fasttext.train_with_callback(ft.f, a, callback)
+    else:
+        fasttext.train(ft.f, a)
     fasttext.train(ft.f, a)
     ft.set_args(ft.f.getArgs())
     return ft

python/fasttext_module/fasttext/pybind/fasttext_pybind.cc

@@ -12,6 +12,7 @@
 #include <fasttext.h>
 #include <pybind11/numpy.h>
 #include <pybind11/pybind11.h>
+#include <pybind11/functional.h>
 #include <pybind11/stl.h>
 #include <real.h>
 #include <vector.h>
@@ -166,6 +167,13 @@ PYBIND11_MODULE(fasttext_pybind, m) {
         }
       },
       py::call_guard<py::gil_scoped_release>());
+
+  m.def(
+      "train_with_callback",
+      [](fasttext::FastText& ft, fasttext::Args& a, fasttext::FastText::TrainCallback& c) {
+        ft.train(a, c);
+      },
+      py::call_guard<py::gil_scoped_release>());
 
   py::class_<fasttext::Vector>(m, "Vector", py::buffer_protocol())
       .def(py::init<ssize_t>())