A simple Python function to convert integer numbers into Vietnamese pronunciation. Use this function to preprocess text before feeding it into a TTS model. It works best for numbers less than one trillion, as I’m unsure how numbers beyond that are pronounced in Vietnamese — and honestly, such large numbers rarely come up.

int_to_vie_pron.py

import itertools

rule_1_pronunciation_list = ['', 'mốt', 'hai', 'ba', 'tư', 'lăm', 'sáu', 'bảy', 'tám', 'chín']
rule_2_pronunciation_list = ['không', 'một', 'hai', 'ba', 'bốn', 'năm', 'sáu', 'bảy', 'tám', 'chín']

# no support for decimal numbers, because honestly I don't really know now to pronounce them in Vietnamese
# although I'm a native speaker.

a = 123123213
def pronounce_number(a: int) -> str:
    if a == 0:
        return 'không'
    
    suffix_cycle = itertools.cycle(['nghìn', 'triệu', 'tỷ'])

    suffix = ''
    result = ''

    prefix = 'âm' if a < 0 else ''
    a = abs(a)

    while a > 0:

        b = a % 1000
        
        b1 = b % 10
        b2 = int(b / 10) % 10
        b3 = int(b / 100)
        if a >= 999: # handle for the remaining 3 digits
            b3_pron = f'{rule_2_pronunciation_list[b3]} trăm' if b2 or b1 else ''
        else:
            b3_pron = '' if not b3 else f'{rule_2_pronunciation_list[b3]} trăm'
        
        b2_pron = '' if not b2 else 'mười' if (b2 == 1) else f'{rule_2_pronunciation_list[b2]} mươi'
        if not b3 and not b2:
            b1_pron = rule_1_pronunciation_list[b1]
        else:
            b1_pron = (('lẻ ' if not b2 and b1 else '') + rule_1_pronunciation_list[b1])
            
        pron = ''
        if b3_pron:
            pron += f'{b3_pron} '
        if b2_pron:
            pron += f'{b2_pron} '
        if b1_pron:
            pron += f'{b1_pron} '
        if pron:
            pron += f'{suffix} '
        pron = pron.strip()
        
        result = f'{pron} {result}'.strip()
        
        suffix = next(suffix_cycle)
        a = a // 1000
        
    if prefix:
        result = f'{prefix} {result}'.strip()
    
    return result.strip()