library.py
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00014 #    disclaimer in the documentation and/or other materials provided
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00033 # Revision $Id: library.py 9993 2010-06-09 02:35:02Z kwc $
00034 """
00035 Top-level library routines we expose to the end-user
00036 """
00037 
00038 from __future__ import with_statement
00039 import yaml
00040 
00041 import roslib.message
00042 import roslib.packages
00043 
00044 import rospy
00045 
00046 def findros(pkg, resource):
00047     """
00048     Find ROS resource inside of a package.
00049 
00050     @param pkg: ROS package name
00051     @type  pkg: str
00052     @param resource: resource filename
00053     @type  resource: str
00054     """
00055     val = roslib.packages.find_resource(pkg, resource)
00056     if val:
00057         return val[0]
00058     else:
00059         raise ROSHException("cannot find resource")
00060     
00061 def YAMLBag(object):
00062     
00063     def __init__(self, filename):
00064         self.filename = filename
00065         self._fp = open(filename, 'w')
00066         
00067     def append(self, msg):
00068         self._fp.write(to_yaml(msg))
00069         
00070     def close(self):
00071         if self._fp is not None:
00072             self._fp.close()
00073             self._fp = None
00074 
00075 def to_yaml(obj):
00076     if isinstance(obj, roslib.message.Message):
00077         return _message_to_yaml(obj)
00078         pass
00079     else:
00080         return yaml.dump(obj)
00081 
00082 def yaml_msg_str(type_, yaml_str, filename=None):
00083     """
00084     Load single message from YAML dictionary representation.
00085 
00086     @param type_: Message class
00087     @type  type_: class (Message subclass)
00088     @param filename: Name of YAML file
00089     @type  filename: str
00090     """
00091     import yaml
00092     if yaml_str.strip() == '':
00093         msg_dict = {}
00094     else:
00095         msg_dict = yaml.load(yaml_str)
00096     if type(msg_dict) != dict:
00097         if filename:
00098             raise ValueError("yaml file [%s] does not contain a dictionary"%filename)
00099         else:
00100             raise ValueError("yaml string does not contain a dictionary")
00101     m = type_()
00102     roslib.message.fill_message_args(m, [msg_dict])
00103     return m
00104         
00105 def yaml_msg(type_, filename):
00106     """
00107     Load single message from YAML dictionary representation.
00108 
00109     @param type_: Message class
00110     @type  type_: class (Message subclass)
00111     @param filename: Name of YAML file
00112     @type  filename: str
00113     """
00114     with open(filename, 'r') as f:
00115         return yaml_msg_str(type_, f.read(), filename=filename)
00116 
00117 def yaml_msgs_str(type_, yaml_str, filename=None):
00118     """
00119     Load messages from YAML list-of-dictionaries representation.
00120 
00121     @param type_: Message class
00122     @type  type_: class (Message subclass)
00123     @param filename: Name of YAML file
00124     @type  filename: str
00125     """
00126     import yaml
00127     yaml_doc = yaml.load(yaml_str)
00128     msgs = []
00129     for msg_dict in yaml_doc:
00130         if not type(msg_dict) == dict:
00131             if filename:
00132                 raise ValueError("yaml file [%s] does not contain a list of dictionaries"%filename)
00133             else:
00134                 raise ValueError("yaml string does not contain a list of dictionaries")
00135         m = type_()
00136         roslib.message.fill_message_args(m, msg_dict)
00137         msgs.append(m)
00138     return msgs
00139         
00140 def yaml_msgs(type_, filename):
00141     """
00142     Load messages from YAML list-of-dictionaries representation.
00143 
00144     @param type_: Message class
00145     @type  type_: class (Message subclass)
00146     @param filename: Name of YAML file
00147     @type  filename: str
00148     """
00149     with open(filename, 'r') as f:
00150         return yaml_msgs_str(type_, f.read(), filename=filename)
00151     
00152 def _message_to_yaml(msg, indent='', time_offset=None):
00153     """
00154     convert value to YAML representation
00155     @param val: to convert to string representation. Most likely a Message.
00156     @type  val: Value
00157     @param indent: indentation
00158     @type  indent: str
00159     @param time_offset: if not None, time fields will be displayed
00160     as deltas from  time_offset
00161     @type  time_offset: Time
00162     """
00163     if type(msg) in [int, long, float, str, bool]:
00164         # TODO: need to actually escape
00165         return msg
00166     elif isinstance(msg, rospy.Time) or isinstance(msg, rospy.Duration):
00167         
00168         if time_offset is not None and isinstance(msg, rospy.Time):
00169             msg = msg-time_offset
00170 
00171         return '\n%ssecs: %s\n%snsecs: %s'%(indent, msg.secs, indent, msg.nsecs)
00172         
00173     elif type(msg) in [list, tuple]:
00174         # have to convert tuple->list to be yaml-safe
00175         if len(msg) == 0:
00176             return str(list(msg))
00177         msg0 = msg[0]
00178         if type(msg0) in [int, float, str, bool] or \
00179                isinstance(msg0, Time) or isinstance(msg0, Duration) or \
00180                type(msg0) in [list, tuple]: # no array-of-arrays support yet
00181             return str(list(msg))
00182         else:
00183             indent = indent + '  '
00184             return "["+','.join([roslib.message.strify_message(v, indent, time_offset) for v in msg])+"]"
00185     elif isinstance(msg, rospy.Message):
00186         if indent:
00187             return '\n'+\
00188                 '\n'.join(['%s%s: %s'%(indent, f,
00189                                        strify_message(getattr(msg, f), '  '+indent, time_offset)) for f in msg.__slots__])
00190         return '\n'.join(['%s%s: %s'%(indent, f, roslib.message.strify_message(getattr(msg, f), '  '+indent, time_offset)) for f in msg.__slots__])
00191     else:
00192         return str(msg) #punt
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fr_tools
Author(s): Armin Hornung, Daniel Maier
autogenerated on Wed Dec 26 2012 16:19:58