code: def next(self):
      fields = list()
      dt = self.data.datetime.date(0).strftime("%Y-%m-%d")
      fields.append(dt)
      if self.data._timeframe < bt.TimeFrame.Days:
          tm = self.data.datetime.time(0).strftime("%H:%M:%S")
          fields.append(tm)
  
      o = "%.2f" % self.data.open[0]
      fields.append(o)
      h = "%.2f" % self.data.high[0]
      fields.append(h)
      l = "%.2f" % self.data.low[0]
      fields.append(l)
      c = "%.2f" % self.data.close[0]
      fields.append(c)
      v = "%d" % self.data.volume[0]
      fields.append(v)
      oi = "%d" % self.data.openinterest[0]
      fields.append(oi)
  
      txt = self.p.separator.join(fields)
      txt += "\n"
      self.f.write(bytes(txt))
  
file_path: backtrader/tools/rewrite-data.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import argparse
  import datetime
  import os.path
  import time
  import sys
  import backtrader
  from backtrader.utils.py3 import bytes
label_desc: Use image node_id 2 for calling the RewriteStrategy obj's underlying member method code with example usage: obj.next() without return types