adding min-frequency option

wani.py

@@ -856,7 +856,7 @@ class Writer:
             return rows
 
         if len(rows[0]) <= self.sort_by:
-            print("Cannot sort by column #{}: Not enough columns!".format(len(rows[0])), file=sys.stderr)
+            logging.warning("Cannot sort by column #{}: Not enough columns!".format(len(rows[0])))
             return rows
         
         try:
@@ -888,17 +888,18 @@ class Writer:
                 to_write.append("") # not yet implemented...
 
             if self.group:
-                if colocation_ids.is_written(cid):
-                    continue
-                else:
+                if colocation_ids.should_write(cid):
                     to_write.append(colocation_ids.num(cid))
                     colocation_ids.set_written(cid)
+                else:
+                    continue
 
             rows.append(to_write)
 
-        rows = self.sorted_rows(rows)
-        file_handler.write("\n".join([", ".join(row) for row in rows]) + "\n")
-        file_handler.flush()
+        if len(rows) > 0:
+            rows = self.sorted_rows(rows)
+            file_handler.write("\n".join([", ".join(row) for row in rows]) + "\n")
+            file_handler.flush()
 
     def write_out(self, matches, structures, colocation_ids):
         def fp_close(fp_):
@@ -923,8 +924,7 @@ class Writer:
                 self.write_header(fp)
 
             sid_matches = matches[s.id]
-            if len(sid_matches) > 0:
-                self.write_out_worker(fp, sid_matches, s.id, s.components, colocation_ids)
+            self.write_out_worker(fp, sid_matches, s.id, s.components, colocation_ids)
 
             if self.multiple_output:
                 fp_close(fp)
@@ -936,6 +936,7 @@ class Writer:
 class ColocationIds:
     def __init__(self):
         self.data = {}
+        self.min_frequency = args.group
 
     def add_match(self, key):
         if key in self.data:
@@ -946,8 +947,8 @@ class ColocationIds:
     def get(self, key, n):
         return self.data[key][n]
 
-    def is_written(self, key):
-        return self.get(key, 2)
+    def should_write(self, key):
+        return self.get(key, 1) >= self.min_frequency and not self.get(key, 2)
 
     def num(self, key):
         return str(self.get(key, 1))
@@ -1048,8 +1049,8 @@ if __name__ == '__main__':
     parser.add_argument('--skip-id-check', help='Skips checks for ids of <w> and <pc>, if they are in correct format', action='store_true')
     parser.add_argument('--lemma-only', help='Will not write word ids, forms and msds in output', action='store_true')
     parser.add_argument('--without-rep', help='Will not write representtaions in output', action='store_true')
-    parser.add_argument('--group', help='Group collocations with same collocation ID', action='store_true')
-    parser.add_argument('--verbose', help='Enable verbose output to stderr', choices=["warning", "info", "debug"], default="info")
+    parser.add_argument('--group', help='Group collocations with same collocation ID', type=int, default=0, const=1, nargs='?')
+    parser.add_argument('--verbose', help='Enable verbose output to stderr', choices=["warning", "info", "debug"], default="info", const="info", nargs='?')
     parser.add_argument('--count-files', help="Count files: more verbose output", action='store_true')
     parser.add_argument('--multiple-output', help='Generate one output for each syntactic structure', action='store_true')