python: Read proxies from environment + no_proxy support

Author: bachorp

modules/openapi-generator/src/main/resources/python/configuration.mustache

@@ -413,6 +413,9 @@ conf = {{{packageName}}}.Configuration(
         self.proxy: Optional[str] = None
         """Proxy URL
         """
+        self.no_proxy: Optional[str] = None
+        """Hosts for which to bypass the proxy
+        """
         self.proxy_headers = None
         """Proxy headers
         """

modules/openapi-generator/src/main/resources/python/rest.mustache

@@ -6,8 +6,11 @@ import io
 import json
 import re
 import ssl
+from urllib.parse import urlparse
+from urllib.request import getproxies
 
 import urllib3
+from requests.utils import should_bypass_proxies
 
 from {{packageName}}.exceptions import ApiException, ApiValueError
 
@@ -89,14 +92,15 @@ class RESTClientObject:
         # https pool manager
         self.pool_manager: urllib3.PoolManager
 
-        if configuration.proxy:
-            if is_socks_proxy_url(configuration.proxy):
+        proxy = getproxies().get(urlparse(configuration.host).scheme) if configuration.proxy is None else configuration.proxy
+        if proxy and not should_bypass_proxies(configuration.host, configuration.no_proxy):
+            if is_socks_proxy_url(proxy):
                 from urllib3.contrib.socks import SOCKSProxyManager
-                pool_args["proxy_url"] = configuration.proxy
+                pool_args["proxy_url"] = proxy
                 pool_args["headers"] = configuration.proxy_headers
                 self.pool_manager = SOCKSProxyManager(**pool_args)
             else:
-                pool_args["proxy_url"] = configuration.proxy
+                pool_args["proxy_url"] = proxy
                 pool_args["proxy_headers"] = configuration.proxy_headers
                 self.pool_manager = urllib3.ProxyManager(**pool_args)
         else: