Implemented filter in rname

pyvisa/rname.py

@@ -11,6 +11,7 @@
 
 from __future__ import division, unicode_literals, print_function, absolute_import
 
+import re
 from collections import namedtuple, defaultdict
 
 from pyvisa import constants
@@ -407,3 +408,20 @@ def to_canonical_name(resource_name):
 
 
 parse_resource_name = ResourceName.from_string
+
+
+def filter(resources, query):
+    """Filter a list of resources according to a query expression.
+
+    The search criteria specified in the query parameter has two parts:
+      1. a VISA regular expression over a resource string.
+      2. optional logical expression over attribute values (not implemented).
+
+    :param resources: iterable of resources.
+    :param query: query expression.
+    """
+
+    query = query.replace('?*', '.*')
+    matcher = re.compile(query, re.IGNORECASE)
+
+    return tuple(res for res in resources if matcher.match(res))

pyvisa/testsuite/test_rname.py

@@ -227,3 +227,18 @@ def test_usb_raw(self):
                          board='2',
                          usb_interface_number='3',
                          canonical_resource_name='USB2::0x1234::125::A22-5::3::RAW')
+
+    def test_filter(self):
+        run_list = (
+            'GPIB0::8::65535::INSTR',
+            'TCPIP0::localhost:1111::inst0::INSTR',
+            'ASRL1::INSTR',
+            'USB0::0x1111::0x2222::0x4445::0::RAW',
+            'USB0::0x1111::0x2222::0x1234::0::INSTR',
+            'TCPIP0::localhost::10001::SOCKET',
+            )
+        self.assertEqual(rname.filter(run_list, '?*::INSTR'),
+                         ('GPIB0::8::65535::INSTR',
+                          'TCPIP0::localhost:1111::inst0::INSTR',
+                          'ASRL1::INSTR',
+                          'USB0::0x1111::0x2222::0x1234::0::INSTR'))