code: def days_traded(begin, end):
      delta = end - begin
      ret = delta.days + 1
      return ret
  
file_path: pyalgotrade/pyalgotrade/stratanalyzer/sharpe.py
imports: from pyalgotrade import stratanalyzer
  from pyalgotrade.stratanalyzer import returns
  from pyalgotrade.utils import stats
  import math
label_desc: Use image node_id 1 for calling a global function with example usage: days_traded(begin, end) and returns: ret