Text Normalization
Text Normalization is part of NeMo's nemo_text_processing - a Python package that is installed with the nemo_toolkit.
It converts text from written form into its verbalized form, e.g. "123" -> "one hundred twenty three".
See NeMo documentation for details.
Tutorial with overview of the package capabilities: Text_(Inverse)_Normalization.ipynb
Tutorial on how to customize the underlying gramamrs: WFST_Tutorial.ipynb