new_contents: #!/usr/bin/env python
  """
  Check that all the functions defined in the chemfiles-sys crate are
  effectivelly used in the chemfiles binding.
  """
  import os
  
  ROOT = os.path.dirname(os.path.dirname(__file__))
  
  
  def functions_list():
      functions = []
      with open(os.path.join(ROOT, "src", "chemfiles", "ffi.py")) as fd:
          for line in fd:
              line = line.strip()
              if line.startswith("# Function"):
                  name = line.split('"')[1]
                  functions.append(name)
      return functions
  
  
  def read_all_source():
      source = ""
      for (dirpath, _, pathes) in os.walk(os.path.join(ROOT, "src")):
          for path in pathes:
              if path != "ffi.py":
                  with open(os.path.join(ROOT, dirpath, path)) as fd:
                      source += fd.read()
      return source
  
  
  def check_functions(functions, source):
      for function in functions:
          if function not in source:
              print("Missing: " + function)
  
  
  if __name__ == '__main__':
      functions = functions_list()
      source = read_all_source()
      check_functions(functions, source)
  
subject: Add a script to check if all function are wraped to Python