From 87ce9aa5c17f763c821017d8157ad185d7ba72ce Mon Sep 17 00:00:00 2001
From: JinZY <zhengyu.jin@gmail.com>
Date: Mon, 23 Aug 2021 17:11:33 +0800
Subject: [PATCH] Support PI User Authentication mode, in the case of when user
 name provided with empty password.

---
 PIconnect/PI.py | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/PIconnect/PI.py b/PIconnect/PI.py
index 45faabc1..da01a1cd 100644
--- a/PIconnect/PI.py
+++ b/PIconnect/PI.py
@@ -79,10 +79,6 @@ def __init__(
         if server and server not in self.servers:
             message = 'Server "{server}" not found, using the default server.'
             warn(message=message.format(server=server), category=UserWarning)
-        if bool(username) != bool(password):
-            raise ValueError(
-                "When passing credentials both the username and password must be specified."
-            )
         if domain and not username:
             raise ValueError(
                 "A domain can only specified together with a username and password."
@@ -92,8 +88,10 @@ def __init__(
             from System.Security import SecureString
 
             secure_pass = SecureString()
-            for c in password:
-                secure_pass.AppendChar(c)
+
+            if password != None:
+                for c in password:
+                    secure_pass.AppendChar(c)
             cred = [username, secure_pass] + ([domain] if domain else [])
             self._credentials = (NetworkCredential(*cred), int(authentication_mode))
         else: