new_contents: import numpy as np
  import pandas as pd
  
  # The controls that are selected to got with cases could be either
  # consultation controls (i.e. a random selection of consultations from
  # any animals not represented in the cases dataset) or animal
  # controls (i.e. a random selection of animals that are not represented in
  # the case dataset). In the latter case, consultation-specific information
  # will need to be collapsed over animal to produce animal-based information.
  
  # It is assumed the cases and controls are stored in the same dataframe.
  # The dataframe will have the following structure:
  # 
  # 
  #     | consultID | patientID | case | var1 | var2 | var3 |
  #     |-----------|-----------|------|------|------|------|
  #     |      1001 |      7324 |   no |    a |  454 |  low |
  #     |      1002 |      7324 |  yes |    a |  454 |  low |
  #     |      1003 |      7324 |   no |    a |  454 |  low |
  #     |      1004 |      7324 |   no |    a |  454 |  low |
  
subject: Create phjPrelimPrepForSelectData.py