Add progress bar in function _split

mkdata.py

@@ -88,7 +88,7 @@ if __name__ == "__main__":
                 gzip.open(test_outfile, "wt", encoding="UTF-8") as testfile, \
                 gzip.open(args.input, "rt", encoding="UTF-8") as infile:
             itrain, idev, itest = 0, 0, 0
-            for i, l in enumerate(infile):
+            for i, l in tqdm(enumerate(infile), total=n):
                 outfile = None
                 if itrain < len(train_ids) and train_ids[itrain] == i:
                     itrain += 1