The best way to get py3k support: same source runs on both, with some contortions.

1 files changed, 54 insertions, 0 deletions

diff --git a/test/backtest.py b/test/backtest.py
new file mode 100644
index 00000000..21a14d6d
--- /dev/null
+++ b/test/backtest.py
@@ -0,0 +1,54 @@
+"""Add things to old Pythons so I can pretend they are newer, for tests."""
+
+# pylint: disable-msg=W0622
+# (Redefining built-in blah)
+# The whole point of this file is to redefine built-ins, so shut up about it.
+
+import os, sys
+
+# Py2k and 3k don't agree on how to run commands in a subprocess.
+try:
+    import subprocess
+except ImportError:
+    def run_command(cmd):
+        """Run a command in a subprocess.
+        
+        Returns the exit code and the combined stdout and stderr.
+        
+        """
+        _, stdouterr = os.popen4(cmd)
+        return 0, stdouterr.read()
+else:
+    def run_command(cmd):
+        """Run a command in a subprocess.
+        
+        Returns the exit code and the combined stdout and stderr.
+        
+        """
+
+        if sys.hexversion > 0x03000000 and cmd.startswith("coverage "):
+            # We don't have a coverage command on 3.x, so fix it up to call the
+            # script. Eventually we won't need this.
+            cmd = "python " + sys.prefix + os.sep + "Scripts" + os.sep + cmd
+
+        proc = subprocess.Popen(cmd, shell=True,
+                stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                stderr=subprocess.STDOUT
+                )
+        retcode = proc.wait()
+        
+        # Get the output, and canonicalize it to strings with newlines.
+        output = proc.stdout.read()
+        if not isinstance(output, str):
+            output = output.decode('utf-8')
+        output = output.replace('\r', '')
+        
+        return retcode, output
+
+# No more execfile in Py3k
+try:
+    execfile = execfile
+except NameError:
+    def execfile(filename, globs):
+        """A Python 3 implementation of execfile."""
+        exec(compile(open(filename).read(), filename, 'exec'), globs)