make method naming consistent (snake case)

toolkit.py

@@ -305,7 +305,7 @@ class KerasROOTClassification:
     def evaluate(self):
         pass
 
-    def writeFriendTree(self):
+    def write_friend_tree(self):
         pass
 
 
@@ -354,7 +354,7 @@ class KerasROOTClassification:
         fig.savefig(os.path.join(plot_dir, "var_{}.pdf".format(var_index)))
 
 
-    def plotROC(self):
+    def plot_ROC(self):
 
         logger.info("Plot ROC curve")
         fpr, tpr, threshold = roc_curve(self.y_test, self.scores_test, sample_weight = self.w_test)
@@ -375,7 +375,7 @@ class KerasROOTClassification:
         plt.clf()
 
 
-    def plotScore(self):
+    def plot_score(self):
         pass
 
 
@@ -398,4 +398,4 @@ if __name__ == "__main__":
                                 identifiers = ["DatasetNumber", "EventNumber"])
 
     c.train(epochs=1)
-    c.plotROC()
+    c.plot_ROC()