class_docstr: TradingControl representing a prohibition against holding short positions.
class_docstr_tok: ["TradingControl","representing","a","prohibition","against","holding","short","positions","."]
code: def __init__(self, on_error):
      super(LongOnly, self).__init__(on_error)
  
imports: import abc
  import logbook
  from datetime import datetime
  import pandas
  from six import with_metaclass
  from zipline.errors import AccountControlViolation, TradingControlViolation
  from zipline.utils.input_validation import expect_bounded, expect_types
label_desc: Use image node_id 1 to create a new LongOnly object from inherited base classes: TradingControl with example: obj = LongOnly(on_error)