Transliterate between English and Tamil
For example, transliteration converts எப்பிடி to eppidi (and vice-versa).
Put the files you want to be transliterated in some directory, begin files with tamil characters with the prefix ta_ (ending with .txt). en_ prefix for contents with english characters.
Then run python build_corpus.py --corpus-path <dirname>. This will produce output in files suffixed _out.txt in the <dirname> directory. Take a look at the included corpus/ folder with sample contents.
build_corpus.py internally uses ta_en_transliterate.py or en_ta_transliterate.py which it chooses on a per-file basis based on the prefix in the filename. The tamil to english transliterator basically calls out to Google's transliteration API. English to Tamil transliterator uses the tamil_unicode_map.py which is a mapping between the unicode codepoints to their english character mapping.