UPDATED: you need to pause between reverse and forward commands. still working out why, exactly...

This is for testing rapid reversal in gcode for RepRap, MakerBot, etc. It does a find and replace of M103 and M101 lines in your gcode file.

Detailed instructions are in the top of the file.

Use it like the following:
python RAPID_REVERSALify.py FILE.gcode printRPM reversalRPM waitTime
e.g.:
python RAPID_REVERSALify.py oozebane.gcode 2.857 25 200

you will get the printout:
we will print at 2.857 RPM
we will rapid reverse at 25.0 RPM
we will wait for 200 ms during rapid reversal

and the file:
oozebane_RAPID_REVERSAL.gcode
will be created

First, every M103 command is replaced with:
M103 (Extruder off)
M108 R__REVERSAL_RPM
M102 (Extruder on, RAPID REVERSAL)
G04 P__WAIT_TIME (Wait t/1000 seconds)
M103 (Extruder off)

Then, every M101 command is replaced with:
(reaccelerate to prev position)
M108 R__REVERSAL_RPM
M101 (Extruder on, RAPID FORWARD)
G04 P_WAIT_TIME (Wait t/1000 seconds)
M103 (Extruder off)
M108 R__PRINT_RPM
M101 (Extruder on, forward)