Improve string concat peformance.

Author: tzonghao

influxdb/_dataframe_client.py

@@ -39,7 +39,7 @@ def write_points(self, dataframe, measurement, tags=None,
         :param dataframe: data points in a DataFrame
         :param measurement: name of measurement
         :param tags: dictionary of tags, with string key-values
-        :param time_precision: [Optional, default 's'] Either 's', 'ms', 'u'
+        :param time_precision: [Optional, default None] Either 's', 'ms', 'u'
             or 'n'.
         :param batch_size: [Optional] Value to write the points in batches
             instead of all at one time. Useful for when doing data dumps from
@@ -140,7 +140,7 @@ def _convert_dataframe_to_json(self, dataframe, measurement, tags=None):
             {'measurement': measurement,
              'tags': tags if tags else {},
              'fields': rec,
-             'time': ts.isoformat()
+             'time': ts.value
              }
             for ts, rec in zip(dataframe.index, dataframe.to_dict('record'))]
         return points
@@ -150,8 +150,8 @@ def _datetime_to_epoch(self, datetime, time_precision='s'):
         if time_precision == 's':
             return seconds
         elif time_precision == 'ms':
-            return seconds * 10 ** 3
+            return seconds * 1e3
         elif time_precision == 'u':
-            return seconds * 10 ** 6
+            return seconds * 1e6
         elif time_precision == 'n':
-            return seconds * 10 ** 9
+            return seconds * 1e9

influxdb/line_protocol.py

@@ -63,41 +63,51 @@ def make_lines(data):
     Extracts the points from the given dict and returns a Unicode string
     matching the line protocol introduced in InfluxDB 0.9.0.
     """
-    lines = ""
+    lines = []
     static_tags = data.get('tags', None)
     for point in data['points']:
+        elements = []
+
         # add measurement name
-        lines += _escape_tag(_force_text(
+        measurement = _escape_tag(_force_text(
             point.get('measurement', data.get('measurement'))
-        )) + ","
+        ))
+        key_values = [measurement]
 
         # add tags
         if static_tags is None:
             tags = point.get('tags', {})
         else:
             tags = copy(static_tags)
             tags.update(point.get('tags', {}))
+
         # tags should be sorted client-side to take load off server
         for tag_key in sorted(tags.keys()):
             key = _escape_tag(tag_key)
             value = _escape_tag(tags[tag_key])
             if key != '' and value != '':
-                lines += "{key}={value},".format(key=key, value=value)
-        lines = lines[:-1] + " "  # strip the trailing comma
+                key_values.append("{key}={value}".format(key=key, value=value))
+        key_values = ','.join(key_values)
+        elements.append(key_values)
 
         # add fields
+        field_values = []
         for field_key in sorted(point['fields'].keys()):
-            lines += "{key}={value},".format(
+            field_values.append("{key}={value}".format(
                 key=_escape_tag(field_key),
                 value=_escape_value(point['fields'][field_key]),
-            )
-        lines = lines[:-1]  # strip the trailing comma
+            ))
+        field_values = ','.join(field_values)
+        elements.append(field_values)
 
         # add timestamp
         if 'time' in point:
-            lines += " " + _force_text(str(int(
+            timestamp = _force_text(str(int(
                 _convert_timestamp(point['time'])
             )))
+            elements.append(timestamp)
 
-        lines += "\n"
-    return lines
+        line = ' '.join(elements)
+        lines.append(line)
+    lines = '\n'.join(lines)
+    return lines + '\n'