datetime

時間日期

datetime to string

from datetime import datetime
now = datetime.now()
s = datetime.strftime(now,'%Y-%m-%d %H:%M:%S')

string to datetime

from datetime import datetime
print datetime.strptime('2019-01-01','%Y-%m-%d')

時間格式判斷

try:
    time_format = "%Y-%m-%d %H:%M:%S"
    datetime.datetime.strptime(time, time_format)
except ValueError:
    raise ValueError(f"Incorrect time format! Should be {time_format}")

格式參考：https://www.cnblogs.com/dplearning/p/5737966.html

計算

加減n日

from datetime import datetime, timedelta
time = datetime.now()

# 減1日
time = time - timedelta(days=1)

# 減1年
time = time - timedelta(days=365)

這個方法沒有「年月」的處理，需要換算成天或是改用別的。

參考：https://blog.csdn.net/CSDN__YX/article/details/120050559

耗時

time_monitor = time.time()
print('耗時:', time.time() - time_monitor)