break and continue are unstructured control flow statements which make code harder to read.
Additionally, more recent versions of Python raise a SyntaxError when modules containing
break or continue outside of a loop are imported.
Therefore, these statements should not be used outside of loops.
narg=len(sys.argv)
if narg == 1:
print('@Usage: input_filename nelements nintervals')
break
if narg == 1:
print('@Usage: input_filename nelements nintervals')
sys.exit()