code: def __init__(self):
      self.capital_used = 0.0
      self.starting_cash = 0.0
      self.portfolio_value = 0.0
      self.pnl = 0.0
      self.returns = 0.0
      self.cash = 0.0
      self.positions = Positions()
      self.start_date = None
      self.positions_value = 0.0
  
imports: from warnings import warn
  import pandas
  from catalyst.assets import Asset, Future
  from catalyst.utils.input_validation import expect_types
  from .utils.enum import enum
  from catalyst._protocol import BarData
label_desc: Use image node_id 1 to create a new Portfolio object from inherited base classes: object with example: obj = Portfolio()