Isolate the open/tokenize.open distinction into backward.py

3 files changed, 15 insertions, 10 deletions

diff --git a/coverage/backward.py b/coverage/backward.py
index 425bcc6e..23c0a569 100644
--- a/coverage/backward.py
+++ b/coverage/backward.py
@@ -71,3 +71,13 @@ try:
     import configparser
 except ImportError:
     import ConfigParser as configparser
+
+# Python 3.2 provides `tokenize.open`, the best way to open source files.
+try:
+    import tokenize
+    open_source = tokenize.open
+except AttributeError:
+    def open_source(fname):
+        """Open a source file the best way."""
+        return open(fname, "rU")
+
diff --git a/coverage/codeunit.py b/coverage/codeunit.py
index f54bda5e..55f44a24 100644
--- a/coverage/codeunit.py
+++ b/coverage/codeunit.py
@@ -1,8 +1,8 @@
 """Code unit (module) handling for Coverage."""
 
-import glob, os, tokenize
+import glob, os
 
-from coverage.backward import string_class, StringIO
+from coverage.backward import open_source, string_class, StringIO
 from coverage.misc import CoverageException
 
 
@@ -104,10 +104,7 @@ class CodeUnit(object):
         """Return an open file for reading the source of the code unit."""
         if os.path.exists(self.filename):
             # A regular text file: open it.
-            if hasattr(tokenize, 'open'):  # Python 3.2 and later
-                return tokenize.open(self.filename)
-            else:
-                return open(self.filename)
+            return open_source(self.filename)
 
         # Maybe it's in a zip file?
         source = self.file_locator.get_zip_data(self.filename)
diff --git a/coverage/parser.py b/coverage/parser.py
index 4dca5771..a71ac102 100644
--- a/coverage/parser.py
+++ b/coverage/parser.py
@@ -3,6 +3,7 @@
 import glob, opcode, os, re, sys, token, tokenize
 
 from coverage.backward import set, sorted, StringIO # pylint: disable-msg=W0622
+from coverage.backward import open_source
 from coverage.bytecode import ByteCodes, CodeObjects
 from coverage.misc import nice_pair, CoverageException, NoSource, expensive
 
@@ -22,10 +23,7 @@ class CodeParser(object):
         self.text = text
         if not self.text:
             try:
-                if hasattr(tokenize, 'open'):  # Python 3.2 and later
-                    sourcef = tokenize.open(self.filename)
-                else:
-                    sourcef = open(self.filename, 'rU')
+                sourcef = open_source(self.filename)
                 self.text = sourcef.read()
                 sourcef.close()
             except IOError: