class_docstr: Uses a Pandas DataFrame as the feed source, iterating directly over the
  tuples returned by "itertuples".
  
  This means that all parameters related to lines must have numeric
  values as indices into the tuples
  
  Note:
  
    - The ``dataname`` parameter is a Pandas DataFrame
  
    - A negative value in any of the parameters for the Data lines
      indicates it's not present in the DataFrame
      it is
class_docstr_tok: ["Uses","a","Pandas","DataFrame","as","the","feed","source",",","iterating","directly","over","the","tuples","returned","by","``","itertuples","''",".","This","means","that","all","parameters","related","to","lines","must","have","numeric","values","as","indices","into","the","tuples","Note",":","-","The","``","dataname","``","parameter","is","a","Pandas","DataFrame","-","A","negative","value","in","any","of","the","parameters","for","the","Data","lines","indicates","it","'s","not","present","in","the","DataFrame","it","is"]
code: def start(self):
      super(PandasDirectData, self).start()
  
      # reset the iterator on each start
      self._rows = self.p.dataname.itertuples()
  
file_path: backtrader/backtrader/feeds/pandafeed.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from backtrader.utils.py3 import filter, string_types, integer_types
  from backtrader import date2num
  import backtrader.feed
label_desc: Use image node_id 1 for calling the PandasDirectData obj's underlying member method code with example usage: obj.start() without return types