1 files changed, 59 insertions, 0 deletions
diff --git a/testing/web-platform/tests/tools/py/doc/io.txt b/testing/web-platform/tests/tools/py/doc/io.txt
new file mode 100644
index 000000000..c11308a6d
--- /dev/null
+++ b/testing/web-platform/tests/tools/py/doc/io.txt
@@ -0,0 +1,59 @@
+=======
+py.io
+=======
+
+
+The 'py' lib provides helper classes for capturing IO during
+execution of a program.
+
+IO Capturing examples
+===============================================
+
+``py.io.StdCapture``
+---------------------------
+
+Basic Example::
+
+  >>> import py
+  >>> capture = py.io.StdCapture()
+  >>> print "hello"
+  >>> out,err = capture.reset()
+  >>> out.strip() == "hello"
+  True
+
+For calling functions you may use a shortcut::
+
+  >>> import py
+  >>> def f(): print "hello"
+  >>> res, out, err = py.io.StdCapture.call(f)
+  >>> out.strip() == "hello"
+  True
+
+``py.io.StdCaptureFD``
+---------------------------
+
+If you also want to capture writes to the stdout/stderr
+filedescriptors you may invoke::
+
+  >>> import py, sys
+  >>> capture = py.io.StdCaptureFD(out=False, in_=False)
+  >>> sys.stderr.write("world")
+  >>> out,err = capture.reset()
+  >>> err
+  'world'
+
+py.io object reference
+============================
+
+.. autoclass:: py.io.StdCaptureFD
+    :members: 
+    :inherited-members:
+
+.. autoclass:: py.io.StdCapture
+    :members: 
+    :inherited-members:
+
+.. autoclass:: py.io.TerminalWriter
+    :members: 
+    :inherited-members:
+