code: def get_positions_list(self):
      positions = []
      for asset, pos in iteritems(self.positions):
          if pos.amount != 0:
              positions.append(pos.to_dict())
      return positions
  
imports: from __future__ import division
  import logbook
  import numpy
  from collections import namedtuple
  from math import isnan
  from six import iteritems, itervalues
  from catalyst.finance.performance.position import Position
  from catalyst.finance.transaction import Transaction
  from catalyst.utils.input_validation import expect_types
  import catalyst.protocol
  from catalyst.assets import Future, Asset
  from .position import positiondict
  from catalyst.constants import LOG_LEVEL
label_desc: Use image node_id 10 for calling the PositionTracker obj's underlying member method code with example usage: obj.get_positions_list() and returns: positions