old_contents: import sys
  import unittest, doctest
  
  def all():
      suite = unittest.TestSuite()
      import si, si.register, si.pylab
      suite.addTests(doctest.DocTestSuite(si))
      suite.addTests(doctest.DocTestSuite(si.register))
      suite.addTests(doctest.DocTestSuite(si.units))
      suite.addTests(doctest.DocTestSuite(si.pylab))
  
      import si.mathmodules.sympy
      suite.addTests(doctest.DocTestSuite(si.mathmodules.sympy)) # will test everything itself. add new tests there as well!
  
      # to test if everything works, uncomment the block containing "degree" in unit_from_string
      
      return suite
  
new_contents: import sys
  import unittest, doctest
  
  def all():
      suite = unittest.TestSuite()
      import si, si.register, si.pylab
      suite.addTests(doctest.DocTestSuite(si))
      suite.addTests(doctest.DocTestSuite(si.register))
      suite.addTests(doctest.DocTestSuite(si.units))
      suite.addTests(doctest.DocTestSuite(si.pylab))
  
      import si.mathmodules.sympy
      suite.addTests(doctest.DocTestSuite(si.mathmodules.sympy)) # will test everything itself. add new tests there as well!
  
      # to test if everything works, uncomment the block containing "degree" in unit_from_string
      
      return suite
  
  def run_all():
      runner = unittest.TextTestRunner()
      suite = all()
      runner.run(suite)
  
  if __name__ == "__main__":
      run_all()
  
subject: make tests runnable with 'python -m test'