[Python] remove singleton (#5012)

* updated tests relying on configuration's singleton

* regenerated samples

* removed singleton from templates

* regenerated samples

* removed broken sample and its test

* reverted accidental change

* regenerated security/ samples

* removed singleton from RESTClientObject

* removed unused Configuration import

* reverted unrelated change

* updated usage examples in api_doc template

samples/client/petstore-security-test/python/petstore_api/__init__.py

@@ -23,5 +23,3 @@ from .apis.fake_api import FakeApi
 from .api_client import ApiClient
 
 from .configuration import Configuration
-
-configuration = Configuration()

samples/client/petstore-security-test/python/petstore_api/api_client.py

@@ -59,18 +59,15 @@ class ApiClient(object):
         'object': object,
     }
 
-    def __init__(self, host=None, header_name=None, header_value=None, cookie=None):
-        """
-        Constructor of the class.
-        """
-        self.rest_client = RESTClientObject()
+    def __init__(self, configuration=None, header_name=None, header_value=None, cookie=None):
+        if configuration is None:
+            configuration = Configuration()
+        self.configuration = configuration
+
+        self.rest_client = RESTClientObject(configuration)
         self.default_headers = {}
         if header_name is not None:
             self.default_headers[header_name] = header_value
-        if host is None:
-            self.host = Configuration().host
-        else:
-            self.host = host
         self.cookie = cookie
         # Set default User-Agent.
         self.user_agent = 'Swagger-Codegen/1.0.0/python'
@@ -139,7 +136,7 @@ class ApiClient(object):
             body = self.sanitize_for_serialization(body)
 
         # request url
-        url = self.host + resource_path
+        url = self.configuration.host + resource_path
 
         # perform request and return response
         response_data = self.request(method, url,
@@ -496,13 +493,11 @@ class ApiClient(object):
         :param querys: Query parameters tuple list to be updated.
         :param auth_settings: Authentication setting identifiers list.
         """
-        config = Configuration()
-
         if not auth_settings:
             return
 
         for auth in auth_settings:
-            auth_setting = config.auth_settings().get(auth)
+            auth_setting = self.configuration.auth_settings().get(auth)
             if auth_setting:
                 if not auth_setting['value']:
                     continue
@@ -523,9 +518,7 @@ class ApiClient(object):
         :param response:  RESTResponse.
         :return: file path.
         """
-        config = Configuration()
-
-        fd, path = tempfile.mkstemp(dir=config.temp_folder_path)
+        fd, path = tempfile.mkstemp(dir=self.configuration.temp_folder_path)
         os.close(fd)
         os.remove(path)
 

samples/client/petstore-security-test/python/petstore_api/apis/fake_api.py

@@ -20,7 +20,6 @@ import re
 # python 2 and python 3 compatibility library
 from six import iteritems
 
-from ..configuration import Configuration
 from ..api_client import ApiClient
 
 
@@ -32,13 +31,9 @@ class FakeApi(object):
     """
 
     def __init__(self, api_client=None):
-        config = Configuration()
-        if api_client:
-            self.api_client = api_client
-        else:
-            if not config.api_client:
-                config.api_client = ApiClient()
-            self.api_client = config.api_client
+        if api_client is None:
+            api_client = ApiClient()
+        self.api_client = api_client
 
     def test_code_inject____end__rn_n_r(self, **kwargs):
         """

samples/client/petstore-security-test/python/petstore_api/configuration.py

@@ -22,17 +22,6 @@ from six import iteritems
 from six.moves import http_client as httplib
 
 
-def singleton(cls, *args, **kw):
-    instances = {}
-
-    def _singleton():
-        if cls not in instances:
-            instances[cls] = cls(*args, **kw)
-        return instances[cls]
-    return _singleton
-
-
-@singleton
 class Configuration(object):
     """
     NOTE: This class is auto generated by the swagger code generator program.
@@ -46,8 +35,7 @@ class Configuration(object):
         """
         # Default Base url
         self.host = "https://petstore.swagger.io */ ' \" =end -- \\r\\n \\n \\r/v2 */ ' \" =end -- \\r\\n \\n \\r"
-        # Default api client
-        self.api_client = None
+
         # Temp file folder for downloading files
         self.temp_folder_path = None
 

samples/client/petstore-security-test/python/petstore_api/rest.py

@@ -24,8 +24,6 @@ import re
 from six import PY3
 from six.moves.urllib.parse import urlencode
 
-from .configuration import Configuration
-
 try:
     import urllib3
 except ImportError:
@@ -58,7 +56,7 @@ class RESTResponse(io.IOBase):
 
 class RESTClientObject(object):
 
-    def __init__(self, pools_size=4, maxsize=4):
+    def __init__(self, configuration, pools_size=4, maxsize=4):
         # urllib3.PoolManager will pass all kw parameters to connectionpool
         # https://github.com/shazow/urllib3/blob/f9409436f83aeb79fbaf090181cd81b784f1b8ce/urllib3/poolmanager.py#L75
         # https://github.com/shazow/urllib3/blob/f9409436f83aeb79fbaf090181cd81b784f1b8ce/urllib3/connectionpool.py#L680
@@ -67,37 +65,28 @@ class RESTClientObject(object):
         # http://stackoverflow.com/a/23957365/2985775
 
         # cert_reqs
-        if Configuration().verify_ssl:
+        if configuration.verify_ssl:
             cert_reqs = ssl.CERT_REQUIRED
         else:
             cert_reqs = ssl.CERT_NONE
 
         # ca_certs
-        if Configuration().ssl_ca_cert:
-            ca_certs = Configuration().ssl_ca_cert
+        if configuration.ssl_ca_cert:
+            ca_certs = configuration.ssl_ca_cert
         else:
             # if not set certificate file, use Mozilla's root certificates.
             ca_certs = certifi.where()
 
-        # cert_file
-        cert_file = Configuration().cert_file
-
-        # key file
-        key_file = Configuration().key_file
-
-       # proxy
-        proxy = Configuration().proxy
-
         # https pool manager
-        if proxy:
+        if configuration.proxy:
             self.pool_manager = urllib3.ProxyManager(
                 num_pools=pools_size,
                 maxsize=maxsize,
                 cert_reqs=cert_reqs,
                 ca_certs=ca_certs,
-                cert_file=cert_file,
-                key_file=key_file,
-                proxy_url=proxy
+                cert_file=configuration.cert_file,
+                key_file=configuration.key_file,
+                proxy_url=configuration.proxy
             )
         else:
             self.pool_manager = urllib3.PoolManager(
@@ -105,19 +94,10 @@ class RESTClientObject(object):
                 maxsize=maxsize,
                 cert_reqs=cert_reqs,
                 ca_certs=ca_certs,
-                cert_file=cert_file,
-                key_file=key_file
+                cert_file=configuration.cert_file,
+                key_file=configuration.key_file
             )
 
-        # https pool manager
-        self.pool_manager = urllib3.PoolManager(
-            num_pools=pools_size,
-            cert_reqs=cert_reqs,
-            ca_certs=ca_certs,
-            cert_file=cert_file,
-            key_file=key_file
-        )
-
     def request(self, method, url, query_params=None, headers=None,
                 body=None, post_params=None, _preload_content=True, _request_timeout=None):
         """