Time processing is a common situation in programming, such as converting time types: when the back-end interface passes parameters, it usually passes a timestamp. The timestamp in the interface return value obtained by the front-end usually needs to be formatted before displaying. In Python, modules that handle time include time and datetime.
The time module is a built-in library of Python specially used to process time. It comes with many methods that can convert different time types to each other. For example, you can convert timestamp type into time tuple, time tuple into formatted time, formatted time into timestamp... .
In Python, there are usually several ways to represent time:
import time # 时间戳类型 t1 = time.time() print(t1) r_time = round(t1 * 1000)# 四舍五入，精确到毫秒 print(r_time) ''' 1677555790.7605402 1677555790761 ''' # 时间字符串 t2 = time.asctime() print(t2) ''' Tue Feb 28 11:44:15 2023 ''' # 时间元组 t3 = time.localtime() print(t3) ''' 依次对应：年份，月份，一个月的第几天，几点，几分，几秒，星期几，一年中的第几天，是否为闰年 time.struct_time(tm_year=2023, tm_mon=2, tm_mday=28, tm_hour=11, tm_min=44, tm_sec=53, tm_wday=1, tm_yday=59, tm_isdst=0) '''
Time stamp type can be converted to time tuple, time tuple can be converted to formatted time, formatted time can be converted to timestamp...
# 时间戳<===>时间元组 相互转换 # 1-时间戳转换为时间元组 tt1 = time.localtime(time.time()) print(tt1) ''' time.struct_time(tm_year=2023, tm_mon=2, tm_mday=28, tm_hour=11, tm_min=48, tm_sec=57, tm_wday=1, tm_yday=59, tm_isdst=0) ''' # 2-时间元组转换为时间戳 tt2 = time.mktime(time.localtime()) print(tt2) ''' 1677556220.0 '''
# 时间元组<===>格式化时间 相互转换
# 1-时间元组转换为格式化时间
tt3 = time.localtime()
print(time.strftime("%Y-%m-%d %H:%M:%S".format(tt3)))
'''
2023-02-28 13:52:02
'''
# 2-格式化时间转换为时间元组
tt4 = time.strptime("2023-02-28 11:54:25", "%Y-%m-%d %H:%M:%S")
print(tt4)
'''
time.struct_time(tm_year=2023, tm_mon=2, tm_mday=28, tm_hour=11, tm_min=54, tm_sec=25, tm_wday=1, tm_yday=59, tm_isdst=-1)
'''Between timestamp and formatted time , cannot be directly converted to each other, and the transition of time tuples must be used for conversion.
# 时间戳<===>格式化时间 相互转换
# 1-格式化时间转换为时间戳
time_format = "2023-02-28 19:11:56"
# 先将格式化时间转换为时间元组
time_stamp1 = time.strptime(time_format, "%Y-%m-%d %H:%M:%S")
# 再将时间元组转换为时间戳
tt7 = time.mktime(time_stamp1)
print(tt7)
'''
1677582716.0
'''
# 2-时间戳转换为格式化时间
time_stamp2 = 1677582716.0
tt8 = time.strftime("%Y-%m-%d %H:%M:%S".format(time_stamp2))
print(tt8)
'''
2023-02-28 19:11:56
'''# 指定类型时间转换为时间字符串 # 1-时间元组转换为时间字符串 tt5 = time.asctime(time.localtime()) print(tt5) ''' Tue Feb 28 11:51:05 2023 ''' # 2-时间戳转换为时间字符串 timestamp = 1677582279.0 tt6 = time.ctime(timestamp) print(tt6) ''' Tue Feb 28 11:51:05 2023 '''
Datetime is a module that comes with Python and is used to process time and date. There are three formats for expressing time in Python: timestamp, tuple, and formatted time. Similar to the time module, the datetime module can also convert datetime types into these three types.
The commonly used categories of datetime are:
The date class contains three parameters: year, month, day, and the return format is year-month-day.
import datetime # 设置指定日期 set_date = datetime.date(day=1, month=3, year=2025) print(set_date)# 2025-03-01
# 获取今天日期的年份、月份、日
today = datetime.date.today()
print("标准日期格式:", today.isoformat())# 标准日期格式: 2023-03-01
print("当前日期的三元元祖: 年、第几周、一周的第几天:", today.isocalendar())# 当前日期的三元元祖: 年、第几周、一周的第几天: (2023, 9, 3)
print("当前日期:", today)# 当前日期: 2023-03-01
print("当前年月日:", today.today())# 当前年月日: 2023-03-01
print("当前年份:", today.year)# 当前年份: 2023
print("当前月份:", today.month)# 当前月份: 3
print("当前日:", today.day)# 当前日: 1# 判断今天是这周的第几天
today = datetime.date.today()
print("当前日期是这周的第几天(星期一==0/周日==6):", today.weekday())# 当前日期是这周的第几天(星期一==0/周日==6): 2
print("当前日期是这周的第几天(星期一==1/周日==7):", today.isoweekday())# 当前日期是这周的第几天(星期一==1/周日==7): 3# 当前日期的其他格式
today = datetime.date.today()
print("当前日期的时间字符串形式:", today.ctime())# 当前日期的时间字符串形式: Wed Mar1 00:00:00 2023
print("当前日期的元组形式:", today.timetuple())
print("当前日期的格式化时间形式:", today.strftime("%Y-%m-%d %H:%M:%S"))# 当前日期的格式化时间形式: 2023-03-01 00:00:00# 替换日期
today = datetime.date.today()
new_day = today.replace(year=2038, month=8, day=31)
print("替换后的日期为:", new_day)# 替换后的日期为: 2038-08-31# 指定格式转换为日期
today = datetime.date.today()
t1 = today.fromtimestamp(1691453288)# 注意精确到秒、不是毫秒
print("从时间戳转换为日期:", t1)# 从时间戳转换为日期: 2023-08-08
t2 = today.fromisoformat("2025-03-03")
print("从三元组转换为日期:", t2)# 从三元组转换为日期: 2025-03-03
t3 = today.fromisocalendar(year=2038, week=9, day=7)
print("从三元组转换为日期:", t3)# 从三元组转换为日期: 2038-03-07datetime.time () can pass multiple parameters:
t = datetime.time(hour=12, minute=59, second=59, microsecond=59)# 实例化time对象，传入时、分、秒、微秒
print("当前时间:", t)# 当前时间: 12:59:59.000059
# 常用属性
print("时:", t.hour)# 时: 12
print("分:", t.minute)# 分: 59
print("秒:", t.second)# 秒: 59
print("微秒:", t.microsecond)# 微秒: 59
print("最大时间:", t.max)# 最大时间: 23:59:59.999999
print("最小时间:", t.min)# 最小时间: 00:00:00t = datetime.time(hour=12, minute=59, second=59, microsecond=59)# 实例化time对象，传入时、分、秒、微秒
print("当前时间:", t)# 当前时间: 12:59:59.000059
# 常用方法
print("返回格式化时间:", t.isoformat())# 格式化时间: 12:59:59.000059
print("从格式化时间转换:", t.fromisoformat('12:00:00'))# 从格式化时间转换: 12:00:00
print("转换为格式化时间:", t.strftime("%Y-%m %H:%M:%S"))# 转换为格式化时间: 1900-01 12:59:59dt = datetime.datetime.now()# 实例化datetime类
print("当前日期:", dt)# 当前日期: 2023-03-01 15:17:00.350579
# 常用属性
print("当前年份:", dt.year)# 当前年份: 2023
print("当前月份:", dt.month)# 当前月份: 3
print("当前日:", dt.day)# 当前日: 1
print("时:", dt.hour)# 时: 15
print("分:", dt.minute)# 分: 17
print("秒:", dt.second)# 秒: 0
print("微秒:", dt.microsecond)# 微秒: 350579
print("最大时间:", dt.max)# 最大时间: 9999-12-31 23:59:59.999999
print("最小时间:", dt.min)# 最小时间: 0001-01-01 00:00:00dt = datetime.datetime.now()# 实例化datetime类
print("当前日期:", dt)# 当前日期: 2023-03-01 15:17:00.350579
# 常用方法
print("今天日期时间:", dt.today())# 今天日期时间: 2023-03-01 15:23:55.703063
print("当前日期:", dt.date())# 当前日期: 2023-03-01
print("当前日期时间的格式化输出:", dt.isoformat())# 当前日期时间的格式化输出: 2023-03-01T15:23:55.703063
print("当前日期的三元组:", dt.isocalendar())# 当前日期的三元组: (2023, 9, 3)
print("当前日期一周中的第几天:", dt.isoweekday())# 当前日期一周中的第几天: 3
print("从指定日期时间转换并格式化输出:", dt.fromisoformat("2023-02-28 19:11:56"))# 从指定日期时间转换并格式化输出: 2023-02-28 19:11:56
print("从指定时间戳转换并格式化输出:", dt.fromtimestamp(1677644920))# 从指定时间戳转换并格式化输出: 2023-03-01 12:28:40
print("从三元组转换并格式化输出:", dt.fromisocalendar(year=2025, week=4, day=2))# 从三元组转换并格式化输出: 2025-01-21 00:00:00datetime.timedelta() 类可以传递多个参数，用来表示时间间隔，返回形式为标准时间格式：0:00:00
print(datetime.timedelta(days=3))# 3 days, 0:00:00 print(datetime.timedelta(hours=3))# 3:00:00 print(datetime.timedelta(minutes=10))# 0:10:00 print(datetime.timedelta(milliseconds=5000))# 0:00:05 print(datetime.timedelta(microseconds=5000000))# 0:00:05
timeit 模块提供了多种方法，可以用来测量 Python 小段代码执行时间。它既可以在命令行界面直接使用，也可以通过导入模块进行调用。
timeit 模块定义了三个实用函数和一个公共类，分别为timeit.timeit()方法、timeit.repeat()方法、timeit.default_timer()方法、timeit.Timer类。部分源码如下：
def timeit(stmt="pass", setup="pass", timer=default_timer, number=default_number, globals=None): """Convenience function to create Timer object and call timeit method.""" return Timer(stmt, setup, timer, globals).timeit(number) def repeat(stmt="pass", setup="pass", timer=default_timer, repeat=default_repeat, number=default_number, globals=None): """Convenience function to create Timer object and call repeat method.""" return Timer(stmt, setup, timer, globals).repeat(repeat, number)
从上述源码中可以看出，无论是timeit还是repeat方法，都是先生成Timer对象，然后调用了Timer对象的timeit或repeat函数。
timeit.timeit(stmt='pass', setup='pass', timer=
, number=1000000)
创建一个 Timer 实例，参数分别是：
注：由于 timeit() 正在执行语句，语句中如果存在返回值的话会阻止 timeit() 返回执行时间。timeit() 会取代原语句中的返回值。
"""timeit()方法""" # 统计代码运行时间 # stmt：要测试的代码，setup：初始化导入语句、要传入的变量属性等 tm1 = timeit.timeit(stmt="[i**2 for i in testlist]", setup="testlist=range(1000)", number=3)# 统计代码运行时间 print(tm1)# 0.0007954000000000017 # 统计代码运行时间，setup为复合语句 tm2 = timeit.timeit(stmt="[i**2 for i in testlist]", setup="a=1000;testlist=range(a)", number=3)# 统计代码运行时间 print(tm2)# 0.0007886000000000282
timeit.repeat(stmt='pass', setup='pass', timer=
, repeat=3, number=1000000)
创建一个 Timer 实例，参数分别是：
"""repeat()方法""" # 统计代码运行时间，重复两次，返回结果为列表 # stmt：要测试的代码，setup：初始化导入语句、要传入的变量属性等 tp1 = timeit.repeat(stmt="[i**2 for i in testlist]", setup="testlist=range(1000)", number=3, repeat=5) print(tp1)# [0.0007632000000000194, 0.0007527999999999979, 0.000754300000000041] # 统计代码运行时间，setup为复合语句 tp2 = timeit.repeat(stmt="[i**2 for i in testlist]", setup="a=1000;testlist=range(a)", number=3, repeat=5) print(tp2)# [0.0007581999999999867, 0.0007580999999999838, 0.0007536000000000209]
timeit.default_timer()默认的计时器，一般是 time.perf_counter()，time.perf_counter() 方法能够在任一平台提供最高精度的计时器（它也只是记录了自然时间，记录自然时间会被很多其他因素影响，例如计算机的负载）。
timeit.Timer是计算小段代码执行速度的类：
timer = timeit.Timer(stmt='pass', setup='pass', timer=
timer.timeit(number=10)
timer.repeat(number=10, repeat=5)
构造函数需要的参数有：
前两个参数的默认值都是 'pass'，timer 参数是平台相关的；前两个参数都可以包含多个语句，多个语句间使用分号（;）或新行分隔开。
第一次测试语句的时间，可以使用 timeit() 方法；repeat() 方法相当于持续多次调用 timeit() 方法并将结果返回为一个列表。
stmt 和 setup 参数也可以是可供调用但没有参数的对象，这将会在一个计时函数中嵌套调用它们，然后被 timeit() 所执行。注意，由于额外的调用，计时开销会相对略到。
"""Timer类""" timer = timeit.Timer(stmt="[i**2 for i in testlist]", setup="a=1000;testlist=range(a)") # 调用timeit方法 print(timer.timeit(number=3))# 0.0008310999999999735 # 调用repeat方法，返回一个时间列表 print(timer.repeat(number=3, repeat=3))# [0.0007549000000000028, 0.0007492000000000054, 0.0007519999999999749]
通过"python -m timeit -h"查看帮助信息：
Tool for measuring execution time of small code snippets.
用于测量小代码片段执行时间的工具。
This module avoids a number of common traps for measuring execution
times. See also Tim Peters' introduction to the Algorithms chapter in
the Python Cookbook, published by O'Reilly.
This module avoids many common techniques for measuring execution Trap time. See also Tim Peters' Python Cookbook, published by O'Reilly.
Library usage: see the Timer class.
Library usage: see the Timer class.
Command line usage:
Command line usage:
python timeit.py [-n N] [-r N] [-s S] [-p] [ -h] [--] [statement]
Options: Options:
-n/--number N: how many times to execute 'statement' (default: see below)
-r/--repeat N: how many times to repeat the timer (default 5)
-s/--setup S: statement to be executed once initially (default 'pass').
Execution time of this setup statement is NOT timed.
-p/--process: use time.process_time() (default is time.perf_counter())
-v/--verbose: print raw timing results; repeat for more digits precision
-u/--unit: set the output time unit (nsec, usec, msec, or sec)
-h/--help: print this usage message and exit
--: separate options from statement, use when statement starts with -
statement: statement to be timed (default 'pass ')
A multi-line statement may be given by specifying each line as a
separate argument; indented lines are possible by enclosing an
argument in quotes and using leading spaces . Multiple -s options are
treated similarly. Space. Multiple -s option inclusions are handled similarly.
If -n is not given, a suitable number of loops is calculated by trying
successive powers of 10 until the total time is at least 0.2 seconds.
If not Given -n, tries until the total time is at least 0.2 seconds.
Note: there is a certain baseline overhead associated with executing a
pass statement. It differs between versions. The code here doesn't try
to hide it, but you should be aware of it. The baseline overhead can be
measured by invoking the program without arguments.
Note: Execute the pass statement. It varies between versions. The code here makes no attempt to hide it, but you should be aware of it. Baseline overhead can be measured by calling the program without parameters.
Classes:
Timer
Functions:
timeit(string, string) -> float
repeat(string, string) -> list
default_timer() -> float
Specific usage:
python timeit.py [-n N] [-r N] [-s S] [ -p] [-h] [--] [statement]
The meaning of each option:
| ##Options | ##Prototype##-n N | |
| --number=N | The number of times the statement has been executed | |
-r N | --repeat=N | Repeat the test Times (default 5 times) |
| ##-s S | --setup=S | Initial execution statement, such as: variables, attributes to be passed in, etc. |
| -p | --process | Measure process time instead of actual execution time (use time.process_time() instead of the default time.perf_counter()) |
| -v | --verbose | Print raw timing results; repeat for more numbers Precision |
| -u | --unit | Set output Time unit (nsec, usec, msec or sec) |
| -h | --help | Output help information |
-- | Separate the options from the statement, use - | |
| ##statement |
这种场景主要适用于在接口传参时的时间日期转换，因为在后端接口传参中，一般都是用时间戳进行传递，而不是传统的"2023-02-28 19:11:56"格式。例如当前有一个新增车辆的接口，其中部分字段涉及到时间日期转换：道路运输证有效期止、行驶证有效期止：
在页面上我选择的都是2023-03-31，但在真实的接口传参中，会自动将其转换为时间戳的形式：
时间2023-03-31自动转换为了时间戳1680192000000，我们再通过工具将1680192000000转换为正常的格式化时间看看确实为2023-03-31，转换正确：
时间戳转换网站：//m.sbmmt.com/link/6e187996e9cc9d93c5f4452695768290
使用Python进行接口测试或模拟接口调用，也需要传递时间戳，Python中time.time()可以直接获取到当前时间的时间戳，但是获取到的是浮点型的数，可以借助round方法进行四舍五入，然后再*1000，从而精确到毫秒：
# 获取当前时间的时间戳
current_time = time.time()
print(current_time)# 1677635951.946926
timestamp = round(current_time) * 1000
print(timestamp)# 1677635952000
# 将时间戳转换为格式化时间
format_time = time.strftime("%Y-%m-%d %H:%M:%S".format(current_time))
print(format_time)# 2023-03-01 09:59:11将上述代码优化一下，封装成函数，直接进行调用：
def get_current_timestamp():
# 获取当前时间的时间戳
current_time = time.time()
timestamp = round(current_time) * 1000
return timestamp
def timestamp_to_format(timestamp):
# 将时间戳转换为格式化时间
format_time = time.strftime("%Y-%m-%d %H:%M:%S".format(timestamp))
return format_time同样是模拟接口调用，但是在造数据时，时间字段我想要模拟的不是当前时间，而是指定的日期时间，如三小时前、三天前等。以下分别介绍time模块和datetime模块如何快速模拟指定时间：
我们都知道1小时有3600秒，也就是3600*1000毫秒，所以如果是模拟3小时前的时间戳，则只需要拿到当前时间的时间戳-3600*1000*3即可：
def get_current_timestamp(): # 获取当前时间的时间戳 current_time = time.time() timestamp = round(current_time) * 1000 return timestamp three_hour_timestamp = get_current_timestamp() - 3600 * 3 * 1000 print(three_hour_timestamp)# 1677630754000
通过站长工具转换时间戳为格式化时间，确实是3个小时前的时间：
使用time模块处理的话需要经过一些计算，而使用datetime模块的timedelta类处理则简单得多，直接填写间隔的时长即可，可以是天、小时、分钟、秒等，获取当前日期时间的三天前的时间戳，整体过程大致分为以下步骤：
# 获取当前日期时间 now_date = datetime.datetime.now() print(now_date)# 2023-03-01 11:47:06.361630 # 获取三天前的日期时间 three_days_ago_date = datetime.datetime.now() - datetime.timedelta(days=3) print(three_days_ago_date) # 将时间元组转换为时间戳 time_tup = int(three_days_ago_date.timestamp() * 1000) print(time_tup)# 1677399019273
这种情况常常用在文件命名上，比如日志文件，通过文件名，可以区分是具体是什么日期时间生成的日志。例如：
# 定义log生成路径、log文件名称
logTime = time.strftime('%Y_%m_%d-%H_%M_%S', time.localtime(time.time()))
# logPath = os.path.dirname(os.path.abspath('.')) + '\log\'
logPath = os.path.dirname(os.path.dirname(os.path.abspath(__file__))) + '\logs\'
logName = logPath + logger + "_" + logTime + '.log'生成的日志文件如下：
在之前介绍装饰器的时候，我们有个案例就是通过time模块来统计代码运行时间的，示例如下：
def timer(func):
def wrapper(*args, **kwargs):
start_time = time.time()
res = func(*args, **kwargs)
end_time = time.time()
timer = end_time - start_time
print("%s函数运行共耗时: %s秒" % (func.__name__, timer))
return res
return wrapper
@timer
def run_timer():
time.sleep(1)
print("测试---统计函数运行时间")
run_timer()
'''
测试---统计函数运行时间
run_timer函数运行共耗时: 1.0101909637451172秒
'''import time
import timeit
def run_time():
# 被测函数
time.sleep(1)
print("used 1 second")
# 统计代码运行时间
# stmt：要测试的代码，setup：要传入的变量属性等，number：每次测量中语句被执行的次数
tt = timeit.timeit(stmt=lambda: run_time(), number=3)
print(tt)
'''
used 1 second
used 1 second
used 1 second
3.001044
'''
# 统计代码运行时间，返回结果为列表
# stmt：要测试的代码，setup：要传入的变量属性等，repeat：重复测试的次数，number：每次测量中语句被执行的次数
tp = timeit.repeat(stmt="[i * 2 for i in testlist]", setup="testlist=range(1000)", repeat=5, number=1)
print(tp)
'''
[0.00011680000000025004, 9.259999999988722e-05, 8.76000000000765e-05]
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