pysrt has an option to split a srt file, but the opposite operation, merging two .srt files, is not possible.
The wiki page shows a method to do so, but the numbering of the entries is wrong: at the middle, where we second half starts, the numbering starts at 1 again.
1
00:00:02,002 --> 00:00:24,441
...
2
00:00:43,210 --> 00:00:47,214
...
1
01:04:04,667 --> 01:04:06,085
...
2
01:04:08,629 --> 01:04:11,966
...
