Catching a traceback

[Terry Reedy]

>     def write( self, text ):
>         self.text += text

With strings, += n times takes O(n**2) time, whereas n appends and join is
O(n).  While ok to use when one knows for sure that n will be small, this
strike me as a bad pattern to post publicly, without comment, where new
Pythoneers might get the wrong idea (as evidenced by some past postings
;-).  For tracebacks, n is usually definitely small but the occasional n up
to maybe 50 might not be considered so.

Terry J. Reedy