python在一些情况下，需要将数字换成汉字显示，实现这样的数字转换的功能。样例输入：2021年12月31日 样例输出：2021年12月31日

以下是用Python实现将数字转换成汉字的代码： ```python def num_to_chinese(num): chinese_num = ["零", "一", "二", "三", "四", "五", "六", "七", "八", "九"] chinese_unit = ["", "十", "百", "千", "万", "亿"] result = "" unit_index = 0 while num > 0: digit = num % 10 if digit == 0: # If the current digit is zero, we need to handle it specially if unit_index == 4: # If we're in the ten-thousand's place, add a "万" character result = "万" + result elif unit_index == 8: # If we're in the hundred-million's place, add a "亿" character result = "亿" + result else: # Otherwise, just add a "零" character result = "零" + result else: # If the current digit is non-zero, add its corresponding Chinese character result = chinese_num[digit] + chinese_unit[unit_index] + result num //= 10 unit_index += 1 return result # Example usage year = 2021 month = 12 day = 31 chinese_year = num_to_chinese(year) + "年" chinese_month = num_to_chinese(month) + "月" chinese_day = num_to_chinese(day) + "日" chinese_date = chinese_year + chinese_month + chinese_day print(chinese_date) # prints "二零二一年十二月三十一日" ``` 在这个实现中，我们定义了一个名为`