1 import types
   2 from types import DictType, ListType, TupleType, InstanceType
   3 import re
   4 
   5 def dump(data):
   6     return "---" + _dump(data,"\n") + "\n"
   7 
   8 def _dump(data, indent):
   9     if (data is None):
  10         return ' ~'
  11     if type(data) is DictType:
  12         return dumpDict(data, indent)
  13     elif type(data) in [ListType, TupleType]:
  14         return dumpList(data, indent)
  15     elif type(data) is InstanceType:
  16         if hasMethod(data, 'to_yaml'):
  17             return _dump(data.to_yaml(), indent)
  18         else:
  19             return dumpDict(data.__dict__, indent)
  20     else:
  21         return dumpScalar(data, indent)
  22 
  23 def dumpDict(data, indent):
  24     output = ""
  25     keys = data.keys()
  26     keys.sort()
  27     for key in keys:
  28         output += "%s%s:%s" % \
  29             (indent, quote(key), _dump(data[key], indent+"    "))
  30     return output
  31 
  32 def dumpList(data, indent):
  33     output = ""
  34     for item in data:
  35         output += "%s-%s" % \
  36             (indent, _dump(item, indent+"    "))
  37     return output
  38 
  39 def quote(data):
  40     single = "'"
  41     double = '"'
  42     quote = ''
  43     if (re.search(r"\t", data) or data[0] == single):
  44         data = `data`[1:-1]
  45         quote = double
  46     if (re.search(r'[-:]', data) or re.search(r'(\d\.){2}', data)):
  47         quote = single
  48     return "%s%s%s" % (quote, data, quote)
  49 
  50 def dumpScalar(data, indent):
  51     data = str(data)
  52     lines = data.splitlines()
  53     if len(lines) == 1:
  54         return " " + quote(data)
  55     return dumpMultiLineScalar(lines, indent)
  56 
  57 def dumpMultiLineScalar(lines, indent):
  58     output = " |"
  59     for line in lines:
  60         output += indent + line
  61     return output
  62 
  63 def hasMethod(object, method_name):
  64     klass = object.__class__
  65     if not hasattr(klass, method_name):
  66         return 0
  67     method = getattr(klass, method_name)
  68     if not callable(method):
  69         return 0
  70     return 1