Add create mode to open()

Lib/test/test_fileio.py

 # Adapted from test_file.py by Daniel Stutzbach
 
 import sys
 import os
 import errno
 import unittest
 from array import array
 from weakref import proxy
 from functools import wraps
 
@@ skipping 380 matching lines @@
         self.assertRaises(TypeError, _FileIO, "1", 0, 0)
 
     def testWarnings(self):
         with check_warnings(quiet=True) as w:
             self.assertEqual(w.warnings, [])
             self.assertRaises(TypeError, _FileIO, [])
             self.assertEqual(w.warnings, [])
             self.assertRaises(ValueError, _FileIO, "/some/invalid/name", "rt")
             self.assertEqual(w.warnings, [])
 
+    def test_create_fail(self):

[Benjamin Peterson, 2012/01/08 16:16:10]

These should really be in test_io.

+        # 'x' mode fails if file is existing
+        with open(TESTFN, 'w'):
+            pass
+        try:
+            self.assertRaises(IOError, _FileIO, TESTFN, 'x')

[Benjamin Peterson, 2012/01/08 16:16:10]

You should check that it's an OSError with the expected errno.

+        finally:
+            os.unlink(TESTFN)
+
+    def test_create_writes(self):
+        # 'x' mode opens for writing
+        with open(TESTFN, 'xb') as f:
+            f.write(b"spam")
+        with open(TESTFN, 'rb') as f:
+            self.assertEqual(b"spam", f.read())

[Charles-François Natali, 2011/12/30 12:49:33]

You should remove the file.

 
 def test_main():
     # Historically, these tests have been sloppy about removing TESTFN.
     # So get rid of it no matter what.
     try:
         run_unittest(AutoFileTests, OtherFileTests)
     finally:
         if os.path.exists(TESTFN):
             os.unlink(TESTFN)
 
 if __name__ == '__main__':
     test_main()