Treat incomplete group keys as distinct when shifting

pandas-dev · Jul 29, 2016 · fe2f0ec · fe2f0ec
1 parent 966d5c6
commit fe2f0ec
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/pandas/src/algos_groupby_helper.pxi b/pandas/src/algos_groupby_helper.pxi
@@ -1359,6 +1359,7 @@ def group_shift_indexer(int64_t[:] out, int64_t[:] labels,
 
                 # Skip null keys
                 if lab == -1:
+                    out[ii] = -1
                     continue
 
                 label_seen[lab] += 1