use /usr/bin/env python instead of /usr/bin/python

Change-Id: I64b60864ecb8981ac54ded15fee1f6ab43a5fba2

doc/user-guide/section_sdk_neutron.xml

@@ -97,7 +97,7 @@ def print_values_server(val, server_id, type):
     <section xml:id="sdk_neutron_create_network">
         <title>Create network</title>
         <para>The following program creates a network:</para>
-        <programlisting language="python">#!/usr/bin/python
+        <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client
@@ -126,7 +126,7 @@ finally:
     <section xml:id="sdk_neutron_list_networks">
         <title>List networks</title>
         <para>The following program lists networks:</para>
-        <programlisting language="python">#!/usr/bin/python
+        <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client
@@ -145,7 +145,7 @@ print_values(netw, 'networks')</programlisting>
     <section xml:id="sdk_neutron_create_port">
         <title>Create ports</title>
         <para>The following program creates a port:</para>
-        <programlisting language="python">#!/usr/bin/python
+        <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client
@@ -187,7 +187,7 @@ if server_detail != None:
     <section xml:id="sdk_neutron_list_ports">
         <title>List ports</title>
         <para>The following program lists ports:</para>
-        <programlisting language="python">#!/usr/bin/python
+        <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client
@@ -209,7 +209,7 @@ print_values(ports, 'ports')</programlisting>
         <title>List server ports</title>
         <para>The following program lists the ports for a
             server:</para>
-        <programlisting language="python">#!/usr/bin/python
+        <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client
@@ -297,7 +297,7 @@ print("Execution Completed")</programlisting>
         </procedure>
         <example>
             <title>Create router: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 from neutronclient.v2_0 import client
 import novaclient.v1_1.client as nvclient
@@ -377,7 +377,7 @@ print("Execution completed")</programlisting>
         </procedure>
         <example>
             <title>Delete network: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 from neutronclient.v2_0 import client
 from credentials import get_credentials
@@ -442,7 +442,7 @@ print("Execution completed")</programlisting>
         </procedure>
         <example>
             <title>List routers: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client
@@ -490,7 +490,7 @@ print(sg)</programlisting>
         </procedure>
         <example>
             <title>List security groups: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client
@@ -541,7 +541,7 @@ print(subnets)</programlisting>
         </procedure>
         <example>
             <title>List subnets: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
 from neutronclient.v2_0 import client

doc/user-guide/section_sdk_nova.xml

@@ -63,7 +63,7 @@ nova_client = Client(**credentials)</programlisting>
         </procedure>
         <example>
             <title>List servers: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 from credentials import get_nova_credentials_v2
 from novaclient.client import Client
@@ -131,7 +131,7 @@ print(nova_client.servers.list)</programlisting>
         </procedure>
         <example>
             <title>Create server: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 import time
 from credentials import get_nova_credentials_v2
@@ -208,7 +208,7 @@ for s in servers_list:
         </procedure>
         <example>
             <title>Delete: complete code listing</title>
-            <programlisting language="python">#!/usr/bin/python
+            <programlisting language="python">#!/usr/bin/env python
 # -*- coding: utf-8 -*-
 from credentials import get_nova_credentials_v2
 from novaclient.client import Client