Use string format instead of replace method

Author: simonkurtz-MSFT

samples/load-balancing/aca-backend-pool-load-balancing.xml

@@ -4,12 +4,12 @@
 <policies>
     <inbound>
         <base />
-        <set-backend-service backend-id="{backend-id}" />
+        <set-backend-service backend-id="{backend_id}" />
     </inbound>
     <backend>
         <!--Apply load-balancing and retry mechanisms -->
         <!--Set count to one less than the number of backends in the pool to try all backends until the backend pool is temporarily unavailable.-->
-        <retry count="{retry-count}" interval="0" first-fast-retry="true" condition="@(context.Response.StatusCode == 429 || (context.Response.StatusCode == 503 && !context.Response.StatusReason.Contains("Backend pool") && !context.Response.StatusReason.Contains("is temporarily unavailable")))">
+        <retry count="{retry_count}" interval="0" first-fast-retry="true" condition="@(context.Response.StatusCode == 429 || (context.Response.StatusCode == 503 && !context.Response.StatusReason.Contains("Backend pool") && !context.Response.StatusReason.Contains("is temporarily unavailable")))">
             <forward-request buffer-request-body="true" />
         </retry>
     </backend>

samples/load-balancing/create.ipynb

@@ -71,10 +71,10 @@
     "\n",
     "# Policies\n",
     "base_policy                                             = './aca-backend-pool-load-balancing.xml'\n",
-    "aca_backend_pool_prioritized_policy_xml                 = utils.read_policy_xml(base_policy).replace('{retry-count}', '1').replace('{backend-id}', 'aca-backend-pool-web-api-429-prioritized')\n",
-    "aca_backend_pool_prioritized_and_weighted_policy_xml    = utils.read_policy_xml(base_policy).replace('{retry-count}', '2').replace('{backend-id}', 'aca-backend-pool-web-api-429-prioritized-and-weighted')\n",
-    "aca_backend_pool_weighted_equal_policy_xml              = utils.read_policy_xml(base_policy).replace('{retry-count}', '1').replace('{backend-id}', 'aca-backend-pool-web-api-429-weighted-50-50')\n",
-    "aca_backend_pool_weighted_unequal_policy_xml            = utils.read_policy_xml(base_policy).replace('{retry-count}', '1').replace('{backend-id}', 'aca-backend-pool-web-api-429-weighted-80-20')\n",
+    "aca_backend_pool_prioritized_policy_xml                 = utils.read_policy_xml(base_policy).format(retry_count = 1, backend_id = 'aca-backend-pool-web-api-429-prioritized')\n",
+    "aca_backend_pool_prioritized_and_weighted_policy_xml    = utils.read_policy_xml(base_policy).format(retry_count = 2, backend_id = 'aca-backend-pool-web-api-429-prioritized-and-weighted')\n",
+    "aca_backend_pool_weighted_equal_policy_xml              = utils.read_policy_xml(base_policy).format(retry_count = 1, backend_id = 'aca-backend-pool-web-api-429-weighted-50-50')\n",
+    "aca_backend_pool_weighted_unequal_policy_xml            = utils.read_policy_xml(base_policy).format(retry_count = 1, backend_id = 'aca-backend-pool-web-api-429-weighted-80-20')\n",
     "\n",
     "# Standard GET Operation\n",
     "get = GET_APIOperation('This is a standard GET')\n",