Renumber a perforce change via p4 python api.

p4_renumber.py

# renumber a change.
# this will create a copy of the change form, without the files
# then reopen the files under the new change.

import argparse
import P4

def renumber(changenum):
   handle = P4.P4()
   handle.connect()
   try:
      # copy the change spec and change attributes
      newspec = handle.fetch_change(changenum)
      files = newspec._files
      newspec._change = 'new'
      newspec._status = 'new'
      newspec._files = []
      # get the text needed for input and create the change
      newdesc = handle.format_change(newspec)
      output = handle.save_change(newdesc)
      newchangenum = output[0].split()[1]
      print 'created changeset %(newchangenum)s from %(changenum)s.' % locals()
      # reopen files in new change
      handle.run_reopen('-c', newchangenum, *files)
      print 'reopened files under changeset %(newchangenum)s.' % locals()
   finally:
      handle.disconnect()


def main():
   parser = argparse.ArgumentParser(description='create a new changelist and reopen associated files.')
   parser.add_argument('changenum', help='the changelist number', type=int)
   args = parser.parse_args()
   renumber(args.changenum)

if __name__ == '__main__':
   main()