new_contents: from db import LinearTransformer, Source, Sink, Scenario, Storage, session
  import pandas as pd
  
  
  def asfloat(x):
      try:
          # do not convert boolean
          return float(x) if not isinstance(x, bool) else x
      except ValueError:
          return x
  
  # path to scenario
  path = '~/oemof/examples/solph/nodes_from_csv/scenarios/'
  
  file_nodes_flows = 'nep_2014.csv'
  file_nodes_flows_sequences = 'nep_2014_seq.csv'
  
  delimiter = ','
  
  # read in csv files
  nodes_flows = pd.read_csv(path + file_nodes_flows, sep=delimiter)
  nodes_flows_seq = pd.read_csv(path + file_nodes_flows_sequences, sep=delimiter,
                                header=None)
  nodes_flows_seq.dropna(axis=0, how='all', inplace=True)
  nodes_flows_seq.drop(0, axis=1, inplace=True)
  nodes_flows_seq = nodes_flows_seq.transpose()
  nodes_flows_seq.set_index([0, 1, 2, 3, 4], inplace=True)
  nodes_flows_seq.columns = range(0, len(nodes_flows_seq.columns))
  nodes_flows_seq = nodes_flows_seq.astype(float)
  
  # create new scenario
  scenario_name = 'nep_2014_test'
  
  sc = Scenario(name=scenario_name)
  session.add(sc)
  session.commit()
  
  # dictionary with all mapped tables
  dc = {'Source': Source, 'LinearTransformer': LinearTransformer,
        'Sink': Sink, 'Storage': Storage}
  
  empty = []
  for idx, series in nodes_flows.iterrows():
  
      # filter for empty rows
      series = series.dropna()
  
      try:
  
          obj = dc[series['class']]()
  
      except KeyError:
          empty.append(idx)
          continue
  
      # map table fields to keys of row series
      for col in obj.__table__.columns.keys():
  
          to_ignore = ['id', 'flow_direction']
  
          if col not in to_ignore and col in series:
  
              if col == 'scenario_id':
                  setattr(obj, col, sc.id)
                  continue
  
              prop = asfloat(series[col])
  
              if prop == 'seq':
                  seq = nodes_flows_seq.loc[series['class'],
                                            series['label'],
                                            series['source'],
                                            series['target'],
                                            col]
                  setattr(obj, col, list(seq))
  
              elif isinstance(prop, float):
                  setattr(obj, col, [prop])
  
              else:
                  setattr(obj, col, prop)
  
      session.add(obj)
  
  print('Comment or empty row at index {li}.'.format(li=empty))
  
  session.commit()
  
subject: Add script file reading csv sc files writing to db