diff --git a/pyvisa-py/serial.py b/pyvisa-py/serial.py
index 36ff2ab4..6818f891 100644
--- a/pyvisa-py/serial.py
+++ b/pyvisa-py/serial.py
@@ -67,8 +67,8 @@ def after_parsing(self):
 
         self.interface = cls(port=self.parsed.board, timeout=2000, writeTimeout=2000)
 
-        for name in 'ASRL_END_IN,ASRL_END_OUT,SEND_END_EN,TERMCHAR,' \
-                    'TERMCHAR_EN,SUPPRESS_END_EN'.split(','):
+        for name in ('ASRL_END_IN', 'ASRL_END_OUT', 'SEND_END_EN', 'TERMCHAR',
+                    'TERMCHAR_EN', 'SUPPRESS_END_EN'):
             attribute = getattr(constants, 'VI_ATTR_' + name)
             self.attrs[attribute] = attributes.AttributesByID[attribute].default
 
diff --git a/pyvisa-py/tcpip.py b/pyvisa-py/tcpip.py
index a862ef85..446769a8 100644
--- a/pyvisa-py/tcpip.py
+++ b/pyvisa-py/tcpip.py
@@ -64,7 +64,7 @@ def after_parsing(self):
         self.link = link
         self.max_recv_size = min(max_recv_size, 2 ** 30)  # 1GB
 
-        for name in 'SEND_END_EN,TERMCHAR,TERMCHAR_EN'.split(','):
+        for name in ('SEND_END_EN', 'TERMCHAR', 'TERMCHAR_EN'):
             attribute = getattr(constants, 'VI_ATTR_' + name)
             self.attrs[attribute] = attributes.AttributesByID[attribute].default
 
@@ -345,7 +345,7 @@ def after_parsing(self):
         self.attrs[constants.VI_ATTR_TCPIP_PORT] = self.parsed.port
         self.attrs[constants.VI_ATTR_INTF_NUM] = self.parsed.board
 
-        for name in 'TERMCHAR,TERMCHAR_EN'.split(','):
+        for name in ('TERMCHAR', 'TERMCHAR_EN'):
             attribute = getattr(constants, 'VI_ATTR_' + name)
             self.attrs[attribute] = attributes.AttributesByID[attribute].default
 
diff --git a/pyvisa-py/usb.py b/pyvisa-py/usb.py
index 0a3fc4bc..2b2c6f95 100644
--- a/pyvisa-py/usb.py
+++ b/pyvisa-py/usb.py
@@ -194,7 +194,7 @@ def after_parsing(self):
                                        int(self.parsed.model_code, 0),
                                        self.parsed.serial_number)
 
-        for name in 'SEND_END_EN,TERMCHAR,TERMCHAR_EN'.split(','):
+        for name in ('SEND_END_EN', 'TERMCHAR', 'TERMCHAR_EN'):
             attribute = getattr(constants, 'VI_ATTR_' + name)
             self.attrs[attribute] = attributes.AttributesByID[attribute].default
 
@@ -228,6 +228,6 @@ def after_parsing(self):
                                              int(self.parsed.model_code, 0),
                                              self.parsed.serial_number)
 
-        for name in 'SEND_END_EN,TERMCHAR,TERMCHAR_EN'.split(','):
+        for name in ('SEND_END_EN', 'TERMCHAR', 'TERMCHAR_EN'):
             attribute = getattr(constants, 'VI_ATTR_' + name)
             self.attrs[attribute] = attributes.AttributesByID[attribute].default