Python 日期（字符串格式）增加n天并返回（字符串格式）

from datetime import datetime
from datetime import timedelta

def date_add(date_str, days_count=1):
    date_list = time.strptime(date_str, "%Y-%m-%d")
    y, m, d = date_list[:3]
    delta = timedelta(days=days_count)
    date_result = datetime(y, m, d) + delta
    date_result = date_result.strftime("%Y-%m-%d")
    return date_result