Efficient string concatenation methods

[Terry Reedy]

> Oliver Crow <ocrow at skymind.com> wrote:
> > I found several sources with advice for how to do concatenation in a
> > pythonic way (e.g. ref#1), but I hadn't seen any measurements or
> > comparisons. So, I put together a little test case and ran it through
> > for six different methods.  Here's the results, and my conclusions:
> >
> > http://www.skymind.com/~ocrow/python_string/
> >
> > I'd be happy to hear if anyone else has done similar tests and if
> > there are any other good candidate methods that I missed.

This

def method4():
  str_list = []
  for num in xrange(loop_count):
    str_list.append(`num`)
  return ''.join(str_list)

will run slightly faster modified to this:

def method4():
  str_list = []
  append = str_list.append
  for num in xrange(loop_count):
    append(`num`)
  return ''.join(str_list)

by factoring the method lookup out of the loop.  Ditto for 3 and 5.

Terry J. Reedy

PS. Changing IE's View/TextSize changes size of header fonts but not body
text, which your CSS apparently fixes at a size a bit small for me on
current system.