FitFile.get_messages remove parsing names to int, remove Python 2 str shim

fitparse/base.py

@@ -5,7 +5,6 @@
 # Python 2 compat
 try:
     num_types = (int, float, long)
-    str = basestring
 except NameError:
     num_types = (int, float)
 
@@ -16,7 +15,7 @@
     BASE_TYPES, BASE_TYPE_BYTE,
     add_dev_data_id, add_dev_field_description, get_dev_type
 )
-from fitparse.utils import fileish_open, FitParseError, FitEOFError, FitCRCError, FitHeaderError
+from fitparse.utils import fileish_open, is_iterable, FitParseError, FitEOFError, FitCRCError, FitHeaderError
 
 
 class FitFile(object):
@@ -407,17 +406,10 @@ def get_messages(self, name=None, with_definitions=False, as_dict=False):
             as_dict = False
 
         if name is not None:
-            if isinstance(name, (tuple, list)):
-                names = name
+            if is_iterable(name):
+                names = set(name)
             else:
-                names = [name]
-
-            # Convert any string numbers in names to ints
-            # TODO: Revisit Python2/3 str/bytes typecheck issues
-            names = set([
-                int(n) if (isinstance(n, str) and n.isdigit()) else n
-                for n in names
-            ])
+                names = set((name,))
 
         def should_yield(message):
             if with_definitions or message.type == 'data':

fitparse/utils.py

@@ -1,6 +1,6 @@
-import re
-
 import io
+import re
+from collections import Iterable
 
 
 class FitParseError(ValueError):
@@ -56,3 +56,10 @@ def fileish_open(fileish, mode):
     else:
         # Python 3 - file contents
         return io.BytesIO(fileish)
+
+
+def is_iterable(obj):
+    """Check, if the obj is iterable but not string or bytes.
+    :rtype bool"""
+    # Speed: do not use iter() although it's more robust, see also https://stackoverflow.com/questions/1952464/
+    return isinstance(obj, Iterable) and not isinstance(obj, (str, bytes))

tests/test_utils.py

@@ -5,7 +5,7 @@
 import sys
 import tempfile
 
-from fitparse.utils import fileish_open
+from fitparse.utils import fileish_open, is_iterable
 
 if sys.version_info >= (2, 7):
     import unittest
@@ -61,6 +61,16 @@ def test_fopen(fileish):
             except OSError:
                 pass
 
+    def test_is_iterable(self):
+        self.assertFalse(is_iterable(None))
+        self.assertFalse(is_iterable(1))
+        self.assertFalse(is_iterable('1'))
+        self.assertFalse(is_iterable(b'1'))
+
+        self.assertTrue(is_iterable((1, 2)))
+        self.assertTrue(is_iterable([1, 2]))
+        self.assertTrue(is_iterable(range(2)))
+
 
 if __name__ == '__main__':
     unittest.main()