fix: backslash escaping in serialization to Line protocol (#303)

Author: bednar

CHANGELOG.md

@@ -12,6 +12,7 @@
 1. [#283](https://github.com/influxdata/influxdb-client-python/pull/283): Set proxy server in config file
 1. [#290](https://github.com/influxdata/influxdb-client-python/pull/290): `Threshold` domain models mapping 
 1. [#290](https://github.com/influxdata/influxdb-client-python/pull/290): `DashboardService` responses types
+1. [#303](https://github.com/influxdata/influxdb-client-python/pull/303): Backslash escaping in serialization to Line protocol
 
 ## 1.19.0 [2021-07-09]
 

influxdb_client/client/write/point.py

@@ -18,7 +18,6 @@
 DEFAULT_WRITE_PRECISION = WritePrecision.NS
 
 _ESCAPE_MEASUREMENT = str.maketrans({
-    '\\': r'\\',      # Note: this is wrong. Backslashes are not escaped like this in measurements.
     ',': r'\,',
     ' ': r'\ ',
     '\n': r'\n',
@@ -27,7 +26,6 @@
 })
 
 _ESCAPE_KEY = str.maketrans({
-    '\\': r'\\',      # Note: this is wrong. Backslashes are not escaped like this in keys.
     ',': r'\,',
     '=': r'\=',
     ' ': r'\ ',

tests/test_point.py

@@ -267,7 +267,7 @@ def test_lineprotocol_encode(self):
         point._tags = {
             "empty_tag": "",
             "none_tag": None,
-            "backslash_tag": "C:\\",
+            "backslash_tag": "C:\\\\",
             "integer_tag": 2,
             "string_tag": "hello"
         }
@@ -379,6 +379,15 @@ def test_unsupported_field_type(self):
 
         self.assertEqual('Type: "<class \'pytz.UTC\'>" of field: "level" is not supported.', f'{exception}')
 
+    def test_backslash(self):
+        point = Point.from_dict({"measurement": "test",
+                                 "tags": {"tag1": "value1", "tag2": "value\2", "tag3": "value\\3",
+                                          "tag4": r"value\4", "tag5": r"value\\5"}, "time": 1624989000000000000,
+                                 "fields": {"value": 10}}, write_precision=WritePrecision.NS)
+        self.assertEqual(
+            "test,tag1=value1,tag2=value\2,tag3=value\\3,tag4=value\\4,tag5=value\\\\5 value=10i 1624989000000000000",
+            point.to_line_protocol())
+
 
 if __name__ == '__main__':
     unittest.main()