1 files changed, 29 insertions, 0 deletions
diff --git a/Lib/test/support.py b/Lib/test/support.py
index 04964a1..611d48f 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -567,6 +567,32 @@ class EnvironmentVarGuard(collections.MutableMapping):
                     del self._environ[k]
             else:
                 self._environ[k] = v
+        os.environ = self._environ
+
+
+class DirsOnSysPath(object):
+    """Context manager to temporarily add directories to sys.path.
+
+    This makes a copy of sys.path, appends any directories given
+    as positional arguments, then reverts sys.path to the copied
+    settings when the context ends.
+
+    Note that *all* sys.path modifications in the body of the
+    context manager, including replacement of the object,
+    will be reverted at the end of the block.
+    """
+
+    def __init__(self, *paths):
+        self.original_value = sys.path[:]
+        self.original_object = sys.path
+        sys.path.extend(paths)
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *ignore_exc):
+        sys.path = self.original_object
+        sys.path[:] = self.original_value
 
 
 class TransientResource(object):
@@ -623,6 +649,9 @@ def captured_output(stream_name):
 def captured_stdout():
     return captured_output("stdout")
 
+def captured_stdin():
+    return captured_output("stdin")
+
 def gc_collect():
     """Force as many objects as possible to be collected.