This script will renumerate the item indexes in a YAML dictionary.

renumerate_param_list.py

#!/usr/bin/env python3

# This script will renumerate the item indexes in a
# YAML dictionary. ROS currently does not support easy
# acquisition of list of objects from parameter server,
# so I prefer using indexed dictionaries. However, it
# is tiring to index them manually. This script does it.
# Example yaml file (iter_prefix = 'p'):
# https://github.com/gokhansolak/lfd-experiments-iros2019/blob/master/data/grasp/pregrasp.yaml

import os, argparse, sys
import re

def renumerate_param_list(filename, it_prefix='i'):
    it_ptr = r'( +'+it_prefix+')\d*:'
    regex_obj = re.compile(it_ptr)

    new_lines = []
    with open(filename, 'r') as f:
        old_lines = f.readlines()

    enum_index = 0
    for line in old_lines:
        new_line = regex_obj.sub(r'\g<1>'+str(enum_index)+':', line)
        # changed? increment
        if regex_obj.match(line):
            enum_index += 1
        new_lines.append(new_line)

    root, ext = os.path.splitext(filename)
    with open(root+'_enum'+ext, 'w') as f:
        f.writelines(new_lines)

    return enum_index

if __name__ == '__main__':

    parser=argparse.ArgumentParser()
    parser.add_argument('-f', '--filename', help='Name of the file incl. extension', required="True")
    parser.add_argument('-i', '--iter_prefix', help='Prefix of the iterator. E.g., k for k0, k1, k2...', default="i")

    args = parser.parse_args()

    last_index = renumerate_param_list(args.filename, args.iter_prefix)

    print('Renumerated '+str(last_index)+' items.')