python: date datetime str之间转换

# 开始日期
import datetime
# 生成date 和datetime 两种格式
begin = datetime.date(2021, 11, 22)
end = datetime.datetime.now().date()
print(type(begin), type(end), begin, end)
# <class 'datetime.date'> <class 'datetime.date'> 2021-11-22 2021-12-17

# 生成date 和datetime 两种格式转换为字符串
begin = datetime.date(2021, 11, 22).strftime("%Y-%m-%d")
end = datetime.datetime.now().date().strftime("%Y-%m-%d")
print(type(begin), type(end), begin, end)
# <class 'str'> <class 'str'> 2021-11-22 2021-12-17

# 字符串2021-12-01转换为date格式
st = "2021-12-01"
et = "2021-12-02"
dt_begin = datetime.datetime.strptime(str(st), "%Y-%m-%d").date()
dt_end = datetime.datetime.strptime(str(et), "%Y-%m-%d").date()
print(type(dt_begin), type(dt_end), dt_begin, dt_end)
# <class 'datetime.date'> <class 'datetime.date'> 2021-12-01 2021-12-02

# 字符串2021-12-01转换为datetime格式
st = "2021-12-01"
et = "2021-12-02"
dt_begin = datetime.datetime.strptime(str(st), "%Y-%m-%d")
dt_end = datetime.datetime.strptime(str(et), "%Y-%m-%d")
print(type(dt_begin), type(dt_end), dt_begin, dt_end)
# <class 'datetime.datetime'> <class 'datetime.datetime'> 2021-12-01 00:00:00 2021-12-02 00:00:00