Emit long strings using yaml multiline syntax

flamel/__init__.py

@@ -22,6 +22,28 @@
 import os
 
 
+# from:
+# http://stackoverflow.com/questions/8640959/how-can-i-control-what-scalar-form-pyyaml-uses-for-my-data  flake8: noqa
+def should_use_block(value):
+    for c in u"\u000a\u000d\u001c\u001d\u001e\u0085\u2028\u2029":
+        if c in value:
+            return True
+    return False
+
+def my_represent_scalar(self, tag, value, style=None):
+    if style is None:
+        if should_use_block(value):
+             style='|'
+        else:
+            style = self.default_style
+
+    node = yaml.representer.ScalarNode(tag, value, style=style)
+    if self.alias_key is not None:
+        self.represented_objects[self.alias_key] = node
+    return node
+
+yaml.representer.BaseRepresenter.represent_scalar = my_represent_scalar
+
 class YamlOrderedLoader(yaml.SafeLoader):
     """Specialized Loader which respects order."""
 
@@ -48,7 +70,7 @@ def unicode_representer(dumper, uni):
     OrderedDumper.add_representer(collections.OrderedDict, _dict_representer)
     OrderedDumper.add_representer(collections.defaultdict, _dict_representer)
     OrderedDumper.add_representer(unicode, unicode_representer)
-    return yaml.dump(data, stream, OrderedDumper, **kwds)
+    return yaml.safe_dump(data, stream, OrderedDumper, **kwds)
 
 
 def yaml_load(data):