1 files changed, 50 insertions, 0 deletions
diff --git a/helpers.py b/helpers.py
index fed4d68..6bba6fd 100644
--- a/helpers.py
+++ b/helpers.py
@@ -146,3 +146,53 @@ def mode_to_kind(mode):
         return 'tree-reference', False
     else:
         raise AssertionError("invalid mode %o" % mode)
+
+
+def binary_stream(stream):
+    """Ensure a stream is binary on Windows.
+
+    :return: the stream
+    """
+    try:
+        import os
+        if os.name == 'nt':
+            fileno = getattr(stream, 'fileno', None)
+            if fileno:
+                no = fileno()
+                if no >= 0:     # -1 means we're working as subprocess
+                    import msvcrt
+                    msvcrt.setmode(no, os.O_BINARY)
+    except ImportError:
+        pass
+    return stream
+
+
+def single_plural(n, single, plural):
+    """Return a single or plural form of a noun based on number."""
+    if n == 1:
+        return single
+    else:
+        return plural
+
+
+def invert_dictset(d):
+    """Invert a dictionary with keys matching a set of values, turned into lists."""
+    # Based on recipe from ASPN
+    result = {}
+    for k, c in d.iteritems():
+        for v in c:
+            keys = result.setdefault(v, [])
+            keys.append(k)
+    return result
+
+
+def invert_dict(d):
+    """Invert a dictionary with keys matching each value turned into a list."""
+    # Based on recipe from ASPN
+    result = {}
+    for k, v in d.iteritems():
+        keys = result.setdefault(v, [])
+        keys.append(k)
+    return result
+
+