如何将字符串中的数字(不考虑位数)转换为特定的字符集？

def convert_numbers_to_letters(string):
    mapping = {
        '0': 'A',
        '1': 'B',
        '2': 'C',
        '3': 'D',
        '4': 'E',
        '5': 'F',
        '6': 'G',
        '7': 'H',
        '8': 'I',
        '9': 'J'
    }
    result = ''
    for char in string:
        if char.isdigit():
            result += mapping[char]
        else:
            result += char
    return result

# 示例用法
string = 'abc123def456'
converted_string = convert_numbers_to_letters(string)
print(converted_string)  # 输出：abcBCDefDEFG