Originally, the argparse module had attempted to maintain compatibility with
optparse. However, optparse was difficult to extend transparently, particularly
with the changes required to support the new ``nargs=`` specifiers and better
-usage messges. When most everything in optparse had either been copy-pasted
+usage messages. When most everything in optparse had either been copy-pasted
over or monkey-patched, it no longer seemed practical to try to maintain the
backwards compatibility.