add deprecation warning for Emitter.indention

lib/yaml/emitter.py

@@ -8,12 +8,16 @@
 
 __all__ = ['Emitter', 'EmitterError']
 
+import warnings
+
 from .error import YAMLError
 from .events import *
 
+
 class EmitterError(YAMLError):
     pass
 
+
 class ScalarAnalysis:
     def __init__(self, scalar, empty, multiline,
             allow_flow_plain, allow_block_plain,
@@ -28,6 +32,7 @@ def __init__(self, scalar, empty, multiline,
         self.allow_double_quoted = allow_double_quoted
         self.allow_block = allow_block
 
+
 class Emitter:
 
     DEFAULT_TAG_PREFIXES = {
@@ -103,6 +108,17 @@ def __init__(self, stream, canonical=None, indent=None, width=None,
         self.analysis = None
         self.style = None
 
+    # backward-compatibility
+    @property
+    def indention(self):
+        warnings.warn("Emitter.indention attribute is deprecated and will be removed in a future release; use Emitter.indentation instead", DeprecationWarning)
+        return self.indentation
+
+    @indention.setter
+    def indention(self, value):
+        warnings.warn("Emitter.indention attribute is deprecated and will be removed in a future release; use Emitter.indentation instead", DeprecationWarning)
+        self.indentation = value
+
     def dispose(self):
         # Reset the state attributes (to clear self-references)
         self.states = []