Allow coverage.py to be executed by pointing Python at a repository's

directory.

Since Python 2.6 one can specify a __main__.py in a directory to tell
Python what to do if it is pointed at simply a directory. For
instance, assuming one has a clone of coverage.py sitting at
../coveragepy, this patch allows for::

  python ../coveragepy run ...

This is extremely handy if you want to use coverage.py straight from a
clone without adding the clone's directory to sys.path (which can be
an issue at least in the stdlib as that will pick up 'test' as a
package, masking the stdlib's own 'test' package).

2 files changed, 17 insertions, 0 deletions

diff --git a/MANIFEST.in b/MANIFEST.in
index 65a60a06..19663a2d 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -9,3 +9,4 @@ include README.txt
 include CHANGES.txt
 include AUTHORS.txt
 prune test
+prune __main__.py
diff --git a/__main__.py b/__main__.py
new file mode 100644
index 00000000..7ad6d737
--- /dev/null
+++ b/__main__.py
@@ -0,0 +1,16 @@
+"""Be able to execute coverage.py by pointing Python at the repository's
+directory."""
+import os
+import runpy
+
+
+PKG = 'coverage'
+
+try:
+    run_globals = runpy.run_module(PKG, run_name='__main__', alter_sys=True)
+    executed = os.path.splitext(os.path.basename(run_globals['__file__']))[0]
+    if executed != '__main__':  # For Python 2.5 compatibility
+        raise ImportError('Incorrectly executed %s instead of __main__' %
+                            executed)
+except ImportError:  # For Python 2.6 compatibility
+    runpy.run_module('%s.__main__' % PKG, run_name='__main__', alter_sys=True)