[python-nextgen] support dict query params (#14727)

* [python-nextgen] convert dictionary query params to string

* [python-nextgen] regenerated samples

* [python-nextgen] added some test cases for parameters_to_url_query

* [python-nextgen] use json.dumps instead of str(v)

* [python-nextgen] update api_client tests

modules/openapi-generator/src/main/resources/python-nextgen/api_client.mustache

@@ -549,6 +549,8 @@ class ApiClient(object):
                 v = str(v)
             if isinstance(v, bool):
                 v = str(v).lower()
+            if isinstance(v, dict):
+                v = json.dumps(v)
 
             if k in collection_formats:
                 collection_format = collection_formats[k]

samples/client/echo_api/python-nextgen/openapi_client/api_client.py

@@ -526,6 +526,8 @@ class ApiClient(object):
                 v = str(v)
             if isinstance(v, bool):
                 v = str(v).lower()
+            if isinstance(v, dict):
+                v = json.dumps(v)
 
             if k in collection_formats:
                 collection_format = collection_formats[k]

samples/openapi3/client/petstore/python-nextgen-aiohttp/petstore_api/api_client.py

@@ -526,6 +526,8 @@ class ApiClient(object):
                 v = str(v)
             if isinstance(v, bool):
                 v = str(v).lower()
+            if isinstance(v, dict):
+                v = json.dumps(v)
 
             if k in collection_formats:
                 collection_format = collection_formats[k]

samples/openapi3/client/petstore/python-nextgen/petstore_api/api_client.py

@@ -525,6 +525,8 @@ class ApiClient(object):
                 v = str(v)
             if isinstance(v, bool):
                 v = str(v).lower()
+            if isinstance(v, dict):
+                v = json.dumps(v)
 
             if k in collection_formats:
                 collection_format = collection_formats[k]

samples/openapi3/client/petstore/python-nextgen/tests/test_api_client.py

@@ -212,3 +212,50 @@ class ApiClientTests(unittest.TestCase):
         self.assertIsNotNone(client._pool)
         atexit._run_exitfuncs()
         self.assertIsNone(client._pool)
+
+    def test_parameters_to_url_query(self):
+        data = 'value={"category": "example", "category2": "example2"}'
+        dictionary = {
+            "category": "example",
+            "category2": "example2"
+        }
+        result = self.api_client.parameters_to_url_query([('value', dictionary)], {})
+        self.assertEqual(result, data)
+        
+        data='value={"number": 1, "string": "str", "bool": true, "dict": {"number": 1, "string": "str", "bool": true}}'
+        dictionary = {
+            "number": 1,
+            "string": "str",
+            "bool": True,
+            "dict": {
+                "number": 1,
+                "string": "str",
+                "bool": True
+            }
+        }
+        result = self.api_client.parameters_to_url_query([('value', dictionary)], {})
+        self.assertEqual(result, data)
+
+        data='value={"strValues": ["one", "two", "three"], "dictValues": [{"name": "value1", "age": 14}, {"name": "value2", "age": 12}]}'
+        dictionary = {
+            "strValues": [
+                "one",
+                "two",
+                "three"
+            ],
+            "dictValues": [
+                {
+                    "name": "value1",
+                    "age": 14
+                },
+                {
+                    "name": "value2",
+                    "age": 12
+                },
+            ]
+        }
+        result = self.api_client.parameters_to_url_query([('value', dictionary)], {})
+        self.assertEqual(result, data)
+
+
+