如何格式化月份中没有前导零的日期？

function formatDateString(dateString) {
  const date = new Date(dateString);
  const year = date.getFullYear();
  const month = (date.getMonth() + 1).toString().padStart(2, '0');
  const day = date.getDate().toString().padStart(2, '0');
  
  return `${year}-${month}-${day}`;
}

const formattedDate = formatDateString('2022-1-5');
console.log(formattedDate); // 输出：2022-01-05

from datetime import datetime

def format_date_string(date_string):
    date = datetime.strptime(date_string, '%Y-%m-%d')
    formatted_date = date.strftime('%Y-%m-%d')
    return formatted_date

formatted_date = format_date_string('2022-1-5')
print(formatted_date)  # 输出：2022-01-05