gistfile1.py

doTypecheck = True

def typecheck( f ):
  def wrapper( *args ):
    global doTypecheck
    if doTypecheck:
      sig = signature( f )
      for k, p in zip( args, sig.parameters.keys() ):
        pv = sig.parameters[p]
        if type( k ) != pv and not isinstance( k, pv ):
          raise TypeError( "The type of parameter '{}' for function '{}', didn't match the " +
                           "expected type '{}' ( got '{}' )".format( p, f.__name__, pv, type( k ) ))
      r = f( *args )
      if type( r ) != sig.return_annotation and not isinstance( r, sig.return_annotation ):
        raise TypeError( "The returned value from '{}' didn't match the expected type '{}'" + 
                         " ( got '{}' )".format( f.__name__, sig.return_annotation, type( r ) ) )
      return r
    else:
      return f( *args )
  return wrapper

@typecheck
def myFunc( x : int, y : str, z : object ) -> Exception:
  return IOError( "Test" )

raise myFunc( 13, "wow", 9.0 )