Tools: filter empty columns out of size_compare result

Tools/scripts/filter_size_compare_branches_csv.py

@@ -13,6 +13,35 @@ class FilterSizeCompareBranchesCSV(object):
     def pretty_print_data(self, data):
         print(tabulate.tabulate(data))
 
+    def prune_empty_columns(self, data):
+        if len(data) == 0:
+            return data
+
+        # populate an array indicating whether here are any non-empty
+        # values in each column:
+        line_length = len(data[0])
+        column_has_content = [False] * line_length
+        for line in data[1:]:  # ASSUMPTION we have a header row!
+            for i in range(line_length):
+                if line[i] != "":
+                    column_has_content[i] = True
+
+        # if all columns are full then we don't need to any more:
+        all_empty = False
+        if not any(column_has_content):
+            return data
+
+        new_data = []
+        for line in data:
+            new_line = []
+            for i in range(line_length):
+                if not column_has_content[i]:
+                    continue
+                new_line.append(line[i])
+            new_data.append(new_line)
+
+        return new_data
+
     def run(self):
         csvt = csv.reader(open(self.filename,'r'))
         data = list(csvt)
@@ -29,6 +58,8 @@ class FilterSizeCompareBranchesCSV(object):
                     new_data.append(line)
             data = new_data
 
+        data = self.prune_empty_columns(data)
+
         self.pretty_print_data(data)
 
 if __name__ == '__main__':