with statements: no more finally close

13 files changed, 26 insertions, 87 deletions

diff --git a/TODO.txt b/TODO.txt
index 30d5bd6..43a3659 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -18,8 +18,9 @@ Key:
     + decorators
     + collections.defaultdict
     + .startswith((,))
-    - "with" statements
+    + "with" statements
     - .format() ?
+    - try/except/finally
 
 + Remove code only run on <2.6
 - Change data file to json
diff --git a/coverage/data.py b/coverage/data.py
index 61b3554..042b640 100644
--- a/coverage/data.py
+++ b/coverage/data.py
@@ -128,11 +128,8 @@ class CoverageData(object):
             self.debug.write("Writing data to %r" % (filename,))
 
         # Write the pickle to the file.
-        fdata = open(filename, 'wb')
-        try:
+        with open(filename, 'wb') as fdata:
             pickle.dump(data, fdata, 2)
-        finally:
-            fdata.close()
 
     def read_file(self, filename):
         """Read the coverage data from `filename`."""
@@ -142,11 +139,8 @@ class CoverageData(object):
         """Return the raw pickled data from `filename`."""
         if self.debug and self.debug.should('dataio'):
             self.debug.write("Reading data from %r" % (filename,))
-        fdata = open(filename, 'rb')
-        try:
+        with open(filename, 'rb') as fdata:
             data = pickle.load(fdata)
-        finally:
-            fdata.close()
         return data
 
     def _read_file(self, filename):
diff --git a/coverage/execfile.py b/coverage/execfile.py
index 5d4ae69..71ec931 100644
--- a/coverage/execfile.py
+++ b/coverage/execfile.py
@@ -129,10 +129,8 @@ def make_code_from_py(filename):
     except IOError:
         raise NoSource("No file to run: %r" % filename)
 
-    try:
+    with source_file:
         source = source_file.read()
-    finally:
-        source_file.close()
 
     # We have the source.  `compile` still needs the last line to be clean,
     # so make sure it is, then compile a code object from it.
@@ -150,7 +148,7 @@ def make_code_from_pyc(filename):
     except IOError:
         raise NoCode("No file to run: %r" % filename)
 
-    try:
+    with fpyc:
         # First four bytes are a version-specific magic number.  It has to
         # match or we won't run the file.
         magic = fpyc.read(4)
@@ -165,7 +163,5 @@ def make_code_from_pyc(filename):
 
         # The rest of the file is the code object we want.
         code = marshal.load(fpyc)
-    finally:
-        fpyc.close()
 
     return code
diff --git a/coverage/html.py b/coverage/html.py
index e026299..d877923 100644
--- a/coverage/html.py
+++ b/coverage/html.py
@@ -43,11 +43,8 @@ def data_filename(fname, pkgdir=""):
 
 def data(fname):
     """Return the contents of a data file of ours."""
-    data_file = open(data_filename(fname))
-    try:
+    with open(data_filename(fname)) as data_file:
         return data_file.read()
-    finally:
-        data_file.close()
 
 
 class HtmlReporter(Reporter):
@@ -140,11 +137,8 @@ class HtmlReporter(Reporter):
 
     def write_html(self, fname, html):
         """Write `html` to `fname`, properly encoded."""
-        fout = open(fname, "wb")
-        try:
+        with open(fname, "wb") as fout:
             fout.write(html.encode('ascii', 'xmlcharrefreplace'))
-        finally:
-            fout.close()
 
     def file_hash(self, source, cu):
         """Compute a hash that changes if the file needs to be re-reported."""
@@ -156,10 +150,8 @@ class HtmlReporter(Reporter):
     def html_file(self, cu, analysis):
         """Generate an HTML file for one source file."""
         source_file = cu.source_file()
-        try:
+        with source_file:
             source = source_file.read()
-        finally:
-            source_file.close()
 
         # Find out if the file on disk is already correct.
         flat_rootname = cu.flat_rootname()
@@ -309,11 +301,8 @@ class HtmlStatus(object):
         usable = False
         try:
             status_file = os.path.join(directory, self.STATUS_FILE)
-            fstatus = open(status_file, "rb")
-            try:
+            with open(status_file, "rb") as fstatus:
                 status = pickle.load(fstatus)
-            finally:
-                fstatus.close()
         except (IOError, ValueError):
             usable = False
         else:
@@ -338,11 +327,8 @@ class HtmlStatus(object):
             'settings': self.settings,
             'files': self.files,
             }
-        fout = open(status_file, "wb")
-        try:
+        with open(status_file, "wb") as fout:
             pickle.dump(status, fout)
-        finally:
-            fout.close()
 
     def settings_hash(self):
         """Get the hash of the coverage.py settings."""
diff --git a/coverage/parser.py b/coverage/parser.py
index 37beede..d0fe997 100644
--- a/coverage/parser.py
+++ b/coverage/parser.py
@@ -25,11 +25,8 @@ class CodeParser(object):
         self.text = text
         if not self.text:
             try:
-                sourcef = open_source(self.filename)
-                try:
+                with open_source(self.filename) as sourcef:
                     self.text = sourcef.read()
-                finally:
-                    sourcef.close()
             except IOError:
                 _, err, _ = sys.exc_info()
                 raise NoSource(
@@ -328,11 +325,8 @@ class ByteParser(object):
         else:
             if not text:
                 assert filename, "If no code or text, need a filename"
-                sourcef = open_source(filename)
-                try:
+                with open_source(filename) as sourcef:
                     text = sourcef.read()
-                finally:
-                    sourcef.close()
             self.text = text
 
             try:
diff --git a/doc/_ext/px_cleaner.py b/doc/_ext/px_cleaner.py
index a5c00ff..2454120 100644
--- a/doc/_ext/px_cleaner.py
+++ b/doc/_ext/px_cleaner.py
@@ -5,17 +5,11 @@ import sys
 def clean_px(fname):
     """Clean a px file."""
 
-    f = open(fname)
-    try:
+    with open(fname) as f:
         text = f.read()
-    finally:
-        f.close()
     text = text.lstrip()
-    f = open(fname, "w")
-    try:
+    with open(fname, "w") as f:
         f.write(text)
-    finally:
-        f.close()
 
 def clean_px_files(fnames):
     for fname in fnames:
@@ -23,4 +17,3 @@ def clean_px_files(fnames):
 
 if __name__ == '__main__':
     clean_px_files(sys.argv[1:])
-
diff --git a/igor.py b/igor.py
index 9f33f15..6c5d56b 100644
--- a/igor.py
+++ b/igor.py
@@ -62,11 +62,8 @@ def run_tests_with_coverage(tracer, *nose_args):
     import nose
     pth_dir = os.path.dirname(os.path.dirname(nose.__file__))
     pth_path = os.path.join(pth_dir, "covcov.pth")
-    pth_file = open(pth_path, "w")
-    try:
+    with open(pth_path, "w") as pth_file:
         pth_file.write("import coverage; coverage.process_startup()\n")
-    finally:
-        pth_file.close()
 
     version = "%s%s" % sys.version_info[:2]
     suffix = "%s_%s_%s" % (version, tracer, socket.gethostname())
diff --git a/setup.py b/setup.py
index e96bdb7..215102b 100644
--- a/setup.py
+++ b/setup.py
@@ -54,11 +54,8 @@ doc = __doc__                   # __doc__ will be overwritten by version.py.
 __version__ = __url__ = ""      # Keep pylint happy.
 
 cov_ver_py = os.path.join(os.path.split(__file__)[0], "coverage/version.py")
-version_file = open(cov_ver_py)
-try:
+with open(cov_ver_py) as version_file:
     exec(compile(version_file.read(), cov_ver_py, 'exec'))
-finally:
-    version_file.close()
 
 doclines = (doc % __url__).splitlines()
 classifier_list = classifiers.splitlines()
diff --git a/tests/coveragetest.py b/tests/coveragetest.py
index f3ca53a..e1c38b2 100644
--- a/tests/coveragetest.py
+++ b/tests/coveragetest.py
@@ -190,11 +190,8 @@ class CoverageTest(TestCase):
             os.makedirs(dirs)
 
         # Create the file.
-        f = open(filename, 'wb')
-        try:
+        with open(filename, 'wb') as f:
             f.write(to_bytes(text))
-        finally:
-            f.close()
 
         return filename
 
@@ -223,17 +220,16 @@ class CoverageTest(TestCase):
 
         """
         modfile = modname + '.py'
-        f = open(modfile, 'r')
 
         for suff in imp.get_suffixes():
             if suff[0] == '.py':
                 break
-        try:
+
+        with open(modfile, 'r') as f:
             # pylint: disable=W0631
             # (Using possibly undefined loop variable 'suff')
             mod = imp.load_module(modname, f, modfile, suff)
-        finally:
-            f.close()
+
         return mod
 
     def start_import_stop(self, cov, modname):
diff --git a/tests/osinfo.py b/tests/osinfo.py
index acbec23..a123123 100644
--- a/tests/osinfo.py
+++ b/tests/osinfo.py
@@ -44,11 +44,8 @@ elif sys.platform == 'linux2':
         """Read the /proc/PID/status file to find memory use."""
         try:
             # get pseudo file /proc/<pid>/status
-            t = open('/proc/%d/status' % os.getpid())
-            try:
+            with open('/proc/%d/status' % os.getpid()) as t:
                 v = t.read()
-            finally:
-                t.close()
         except IOError:
             return 0    # non-Linux?
          # get VmKey line e.g. 'VmRSS:  9999  kB\n ...'
diff --git a/tests/test_data.py b/tests/test_data.py
index 9c29289..31578f2 100644
--- a/tests/test_data.py
+++ b/tests/test_data.py
@@ -92,11 +92,8 @@ class DataTest(CoverageTest):
         covdata.add_line_data(DATA_1)
         covdata.write()
 
-        fdata = open(".coverage", 'rb')
-        try:
+        with open(".coverage", 'rb') as fdata:
             data = pickle.load(fdata)
-        finally:
-            fdata.close()
 
         lines = data['lines']
         self.assertSameElements(lines.keys(), MEASURED_FILES_1)
@@ -111,11 +108,8 @@ class DataTest(CoverageTest):
         covdata.add_arc_data(ARC_DATA_3)
         covdata.write()
 
-        fdata = open(".coverage", 'rb')
-        try:
+        with open(".coverage", 'rb') as fdata:
             data = pickle.load(fdata)
-        finally:
-            fdata.close()
 
         self.assertSameElements(data['lines'].keys(), [])
         arcs = data['arcs']
diff --git a/tests/test_execfile.py b/tests/test_execfile.py
index 24c521b..ca13d7c 100644
--- a/tests/test_execfile.py
+++ b/tests/test_execfile.py
@@ -54,11 +54,8 @@ class RunFileTest(CoverageTest):
         # Make sure we can read any sort of line ending.
         pylines = """# try newlines|print('Hello, world!')|""".split('|')
         for nl in ('\n', '\r\n', '\r'):
-            fpy = open('nl.py', 'wb')
-            try:
+            with open('nl.py', 'wb') as fpy:
                 fpy.write(nl.join(pylines).encode('utf-8'))
-            finally:
-                fpy.close()
             run_python_file('nl.py', ['nl.py'])
         self.assertEqual(self.stdout(), "Hello, world!\n"*3)
 
diff --git a/tests/test_process.py b/tests/test_process.py
index 4453fc5..1ab56e8 100644
--- a/tests/test_process.py
+++ b/tests/test_process.py
@@ -572,16 +572,13 @@ class ProcessStartupTest(CoverageTest):
             g = glob.glob(os.path.join(d, "*.pth"))
             if g:
                 pth_path = os.path.join(d, "subcover.pth")
-                pth = open(pth_path, "w")
-                try:
+                with open(pth_path, "w") as pth:
                     try:
                         pth.write(pth_contents)
                         self.pth_path = pth_path
                         break
                     except (IOError, OSError):          # pragma: not covered
                         pass
-                finally:
-                    pth.close()
         else:                                           # pragma: not covered
             raise Exception("Couldn't find a place for the .pth file")