old_contents: import sys
  
  import numpy
  
  from recordlinkage.types import is_list_like, is_numpy_like
  
  
  # Errors and Exception handlers
  class IndexError(Exception):
      """ Error class for errors related to indexing. """
      pass
  
  # Checks and conversions
  
  
  def listify(x):
      """Make a list of the argument if it is not a list."""
  
      if isinstance(x, list):
          return x
      elif isinstance(x, tuple):
          return list(x)
      else:
          return [x]
  
  
  def unique(x):
      """Convert a list in a unique list."""
  
      return list(set(x))
  
  
  def merge_dicts(*dict_args):
      '''
      Given any number of dicts, shallow copy and merge into a new dict,
      precedence goes to key value pairs in latter dicts.
      '''
      result = {}
      for dictionary in dict_args:
          result.update(dictionary)
      return result
  
  
  def max_number_of_pairs(*args):
      """Compute the maximum number of pairs."""
  
      if not args:
          raise ValueError('expected at least one dataframe')
  
      if len(args) == 1:
          return len(args[0]) * (len(args[0]) - 1) / 2
      else:
          return numpy.prod([len(arg) for arg in args])
  
new_contents: import numpy
  
  
  # Errors and Exception handlers
  class IndexError(Exception):
      """ Error class for errors related to indexing. """
      pass
  
  # Checks and conversions
  
  
  def listify(x):
      """Make a list of the argument if it is not a list."""
  
      if isinstance(x, list):
          return x
      elif isinstance(x, tuple):
          return list(x)
      else:
          return [x]
  
  
  def unique(x):
      """Convert a list in a unique list."""
  
      return list(set(x))
  
  
  def merge_dicts(*dict_args):
      '''
      Given any number of dicts, shallow copy and merge into a new dict,
      precedence goes to key value pairs in latter dicts.
      '''
      result = {}
      for dictionary in dict_args:
          result.update(dictionary)
      return result
  
  
  def max_number_of_pairs(*args):
      """Compute the maximum number of pairs."""
  
      if not args:
          raise ValueError('expected at least one dataframe')
  
      if len(args) == 1:
          return len(args[0]) * (len(args[0]) - 1) / 2
      else:
          return numpy.prod([len(arg) for arg in args])
  
subject: Remove unused imports