From f5f726407717b6f7c56536c3f75638df0d28f5b6 Mon Sep 17 00:00:00 2001
From: Yacine Filali <yfilali@hotmail.com>
Date: Wed, 24 May 2017 13:22:24 -0700
Subject: [PATCH] Can now handle read only classifier data as well

---
 talon/signature/learning/classifier.py | 46 +++++++++++++++++---------
 1 file changed, 31 insertions(+), 15 deletions(-)

diff --git a/talon/signature/learning/classifier.py b/talon/signature/learning/classifier.py
index 9267db0..4e1e886 100644
--- a/talon/signature/learning/classifier.py
+++ b/talon/signature/learning/classifier.py
@@ -7,8 +7,6 @@ body belongs to the signature.
 
 from __future__ import absolute_import
 
-import pickle
-
 from numpy import genfromtxt
 from sklearn.externals import joblib
 from sklearn.svm import LinearSVC
@@ -32,19 +30,37 @@ def train(classifier, train_data_filename, save_classifier_filename=None):
 
 def load(saved_classifier_filename, train_data_filename):
     """Loads saved classifier. """
+    import sys
+    if sys.version_info > (3, 0):
+        return load_compat(saved_classifier_filename)
+
+    return joblib.load(saved_classifier_filename)
+
+
+def load_compat(saved_classifier_filename):
+    import os
+    import pickle
+    import tempfile
+
+    # we need to switch to the data path to properly load the related _xx.npy files
+    cwd = os.getcwd()
+    os.chdir(os.path.dirname(saved_classifier_filename))
+
+    # convert encoding using pick.load and write to temp file which we'll tell joblib to use
+    pickle_file = open(saved_classifier_filename, 'rb')
+    classifier = pickle.load(pickle_file, encoding='latin1')
+
     try:
-        return joblib.load(saved_classifier_filename)
-    except ValueError:
-        # load python 2 pickle format with python 3, and save it permissions allowing
-        import sys
-        kwargs = {}
-        if sys.version_info > (3, 0):
-            kwargs["encoding"] = "latin1"
+        # save our conversion if permissions allow
+        joblib.dump(classifier, saved_classifier_filename)
+    except Exception:
+        # can't write to classifier, use a temp file
+        tmp = tempfile.SpooledTemporaryFile()
+        joblib.dump(classifier, tmp)
+        saved_classifier_filename = tmp
 
-        loaded = pickle.load(open(saved_classifier_filename, 'rb'), **kwargs)
-        try:
-            joblib.dump(loaded, saved_classifier_filename, compress=True)
-        except Exception:
-            pass
+    # important, use joblib.load before switching back to original cwd
+    jb_classifier = joblib.load(saved_classifier_filename)
+    os.chdir(cwd)
 
-        return joblib.load(saved_classifier_filename)
+    return jb_classifier