blocks|key|1363835|text|datetime.timedelta只是两个datetimes之间的差值...所以它就像一段时间，以天/秒/微秒为单位|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1363836|>>>+import+datetime
>>>+a+=+datetime.datetime.now()
>>>+b+=+datetime.datetime.now()
>>>+c+=+b+-+a

>>>+c
datetime.timedelta(0,+4,+316543)
>>>+c.days
0
>>>+c.seconds
4
>>>+c.microseconds
316543|code-block|syntax|javascript|1363837|请注意，c.microseconds仅返回时间增量的微秒部分！出于计时目的，请始终使用c.total_seconds()。|1363838|你可以用datetime.timedelta做各种数学运算，例如：|1363839|>>>+c+/+10
datetime.timedelta(0,+0,+431654)|1363840|不过，查看CPU时间可能比查看挂钟时间更有用……不过，这是依赖于操作系统的。在类Unix系统下，查看“time”命令。|1363841|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.python.org/3.2/library/datetime.html#timedelta-objects^0|0|I|0|I|0|0|0|4|E|17|H|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@$9|13|A|14|1|15]]|E|$]]|$1|F|3|G|5|H|7|16|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|M|3|N|5|6|7|1C|8|@]|D|@]|E|$]]|$1|O|3|P|5|H|7|1D|8|@]|D|@]|E|$I|J]]|$1|Q|3|R|5|6|7|1E|8|@]|D|@]|E|$]]|$1|S|3|-4|5|6|7|1F|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]]]

<a href="http://docs.python.org/3.2/library/datetime.html#timedelta-objects" rel="noreferrer"><code>datetime.timedelta</code></a> is just the difference between two datetimes ... so it's like a period of time, in days / seconds / microseconds

<pre><code>&gt;&gt;&gt; import datetime
&gt;&gt;&gt; a = datetime.datetime.now()
&gt;&gt;&gt; b = datetime.datetime.now()
&gt;&gt;&gt; c = b - a

&gt;&gt;&gt; c
datetime.timedelta(0, 4, 316543)
&gt;&gt;&gt; c.days
0
&gt;&gt;&gt; c.seconds
4
&gt;&gt;&gt; c.microseconds
316543
</code></pre>

Be aware that <code>c.microseconds</code> only returns the microseconds portion of the timedelta! For timing purposes always use <code>c.total_seconds()</code>.

You can do all sorts of maths with datetime.timedelta, eg:

<pre><code>&gt;&gt;&gt; c / 10
datetime.timedelta(0, 0, 431654)
</code></pre>

It might be more useful to look at CPU time instead of wallclock time though ... that's operating system dependant though ... under Unix-like systems, check out the 'time' command.

blocks|key|1364006|text|从Python2.7开始就有了timedelta.total_seconds()方法。因此，要获取经过的毫秒数：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1364007|>>>+import+datetime
>>>+a+=+datetime.datetime.now()
>>>+b+=+datetime.datetime.now()
>>>+delta+=+b+-+a
>>>+print+delta
0:00:05.077263
>>>+int(delta.total_seconds()+*+1000)+#+milliseconds
5077|code-block|syntax|javascript|1364008|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Since Python 2.7 there's the timedelta.total_seconds() method. So, to get the elapsed milliseconds:

<pre><code>&gt;&gt;&gt; import datetime
&gt;&gt;&gt; a = datetime.datetime.now()
&gt;&gt;&gt; b = datetime.datetime.now()
&gt;&gt;&gt; delta = b - a
&gt;&gt;&gt; print delta
0:00:05.077263
&gt;&gt;&gt; int(delta.total_seconds() * 1000) # milliseconds
5077
</code></pre>

blocks|key|1579057|text|您可能希望改用the+timeit+module。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1579058|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.python.org/library/timeit.html^0|7|H|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

You might want to use <a href="http://docs.python.org/library/timeit.html" rel="noreferrer">the timeit module</a> instead.

blocks|key|1579025|text|您还可以使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1579026|import+time

start+=+time.clock()
do_something()
end+=+time.clock()
print+"%25.2gs"+%25+(end-start)|code-block|syntax|javascript|1579027|或者你可以使用python+profilers。|offset|length|1579028|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.python.org/library/profile.html^0|0|0|7|G|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

You could also use:

<pre><code>import time

start = time.clock()
do_something()
end = time.clock()
print "%.2gs" % (end-start)
</code></pre>

Or you could use the <a href="http://docs.python.org/library/profile.html" rel="noreferrer">python profilers</a>.

blocks|key|1363958|text|我知道这有点晚了，但我真的很喜欢用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1363959|import+time
start+=+time.time()

#####+your+timed+code+here+...+#####

print+"Process+time:+"+%2B+(time.time()+-+start)|code-block|syntax|javascript|1363960|time.time()给出了从纪元开始的秒数。因为这是以秒为单位的标准化时间，所以您可以简单地从结束时间中减去开始时间，以获得进程时间(以秒为单位)。time.clock()对于基准测试很好，但是如果你想知道你的过程花了多长时间，我发现它有点无用。例如，说“我的进程需要10秒”要比说“我的进程需要10个处理器时钟单位”更直观。|offset|length|style|CODE|1363961|>>>+start+=+time.time();+sum([each**8.3+for+each+in+range(1,100000)])+;+print+(time.time()+-+start)
3.4001404476250935e%2B45
0.0637760162354
>>>+start+=+time.clock();+sum([each**8.3+for+each+in+range(1,100000)])+;+print+(time.clock()+-+start)
3.4001404476250935e%2B45
0.05|1363962|在上面的第一个示例中，time.clock()的时间是0.05vs.+time.time()的时间是0.06377|1363963|>>>+start+=+time.clock();+time.sleep(1)+;+print+"process+time:+"+%2B+(time.clock()+-+start)
process+time:+0.0
>>>+start+=+time.time();+time.sleep(1)+;+print+"process+time:+"+%2B+(time.time()+-+start)
process+time:+1.00111794472|1363964|在第二个示例中，即使进程休眠了一秒钟，处理器时间也显示为"0“。time.time()正确地显示了略多于1秒的时间。|1363965|entityMap^0|0|0|0|B|23|C|0|0|0|0|W|B|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@$I|Z|J|10|K|L]|$I|11|J|12|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|14|8|@]|9|@]|A|$]]|$1|Q|3|R|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|16|8|@$I|17|J|18|K|L]]|9|@]|A|$]]|$1|U|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|V|$]]

I know this is late, but I actually really like using:

<pre><code>import time
start = time.time()

##### your timed code here ... #####

print "Process time: " + (time.time() - start)
</code></pre>

<code>time.time()</code> gives you seconds since the epoch. Because this is a standardized time in seconds, you can simply subtract the start time from the end time to get the process time (in seconds). <code>time.clock()</code> is good for benchmarking, but I have found it kind of useless if you want to know how long your process took. For example, it's much more intuitive to say "my process takes 10 seconds" than it is to say "my process takes 10 processor clock units"

<pre><code>&gt;&gt;&gt; start = time.time(); sum([each**8.3 for each in range(1,100000)]) ; print (time.time() - start)
3.4001404476250935e+45
0.0637760162354
&gt;&gt;&gt; start = time.clock(); sum([each**8.3 for each in range(1,100000)]) ; print (time.clock() - start)
3.4001404476250935e+45
0.05
</code></pre>

In the first example above, you are shown a time of 0.05 for time.clock() vs 0.06377 for time.time()

<pre><code>&gt;&gt;&gt; start = time.clock(); time.sleep(1) ; print "process time: " + (time.clock() - start)
process time: 0.0
&gt;&gt;&gt; start = time.time(); time.sleep(1) ; print "process time: " + (time.time() - start)
process time: 1.00111794472
</code></pre>

In the second example, somehow the processor time shows "0" even though the process slept for a second. <code>time.time()</code> correctly shows a little more than 1 second.

blocks|key|1363719|text|下面的代码应该显示确定的时间...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1363720|from+datetime+import+datetime

tstart+=+datetime.now()

#+code+to+speed+test

tend+=+datetime.now()
print+tend+-+tstart|code-block|syntax|javascript|1363721|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The following code should display the time detla...

<pre><code>from datetime import datetime

tstart = datetime.now()

# code to speed test

tend = datetime.now()
print tend - tstart
</code></pre>

blocks|key|1363561|text|您可以简单地打印出差异：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1363562|print+tend+-+tstart|code-block|syntax|javascript|1363563|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You could simply print the difference:

<pre><code>print tend - tstart
</code></pre>

blocks|key|1578842|text|我不是Python程序员，而是I+do+know+how+to+use+Google，这是我发现的:您使用"-“运算符。要完成您的代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1578843|from+datetime+import+datetime

tstart+=+datetime.now()

#+code+to+speed+test

tend+=+datetime.now()
print+tend+-+tstart|code-block|syntax|javascript|1578844|此外，看起来您可以使用strftime()函数来格式化timespan计算，以便呈现时间。|1578845|entityMap|0|LINK|mutability|MUTABLE|url|http://pleac.sourceforge.net/pleac_python/datesandtimes.html^0|F|R|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

I am not a Python programmer, but <a href="http://pleac.sourceforge.net/pleac_python/datesandtimes.html" rel="nofollow noreferrer">I do know how to use Google</a> and here's what I found: you use the "-" operator. To complete your code:

<pre><code>from datetime import datetime

tstart = datetime.now()

# code to speed test

tend = datetime.now()
print tend - tstart
</code></pre>

Additionally, it looks like you can use the strftime() function to format the timespan calculation in order to render the time however makes you happy.

blocks|key|1363893|text|您可能需要研究一下profile模块。您将更好地了解您的速度减慢在哪里，并且您的大部分工作将是完全自动化的。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1363894|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.python.org/library/profile.html^0|9|7|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

You may want to look into the <a href="http://docs.python.org/library/profile.html" rel="nofollow noreferrer">profile</a> modules. You'll get a better read out of where your slowdowns are, and much of your work will be full-on automated.

blocks|key|1363771|text|time.time()+/+datetime非常适合快速使用，但并不总是100%25精确。出于这个原因，我喜欢使用std+lib+profilers+(尤其是hotshot)来找出是什么。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1363772|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.python.org/library/profile.html^0|1R|9|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

time.time() / datetime is good for quick use, but is not always 100% precise. For that reason, I like to use one of the std lib <a href="http://docs.python.org/library/profile.html" rel="nofollow noreferrer">profilers</a> (especially hotshot) to find out what's what.

blocks|key|1579183|text|箭头:+Python更好的日期和时间|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1579184|import+arrow
start_time+=+arrow.utcnow()
end_time+=+arrow.utcnow()
(end_time+-+start_time).total_seconds()++#+senconds
(end_time+-+start_time).total_seconds()+*+1000++#+milliseconds|code-block|syntax|javascript|1579185|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Arrow: Better dates &amp; times for Python

<pre><code>import arrow
start_time = arrow.utcnow()
end_time = arrow.utcnow()
(end_time - start_time).total_seconds() # senconds
(end_time - start_time).total_seconds() * 1000 # milliseconds
</code></pre>

blocks|key|1579284|text|您需要改用time.time()，它可以高精度地输出unix时间。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1579285|使用以下代码：|1579286|from+time+import+time

tstart+=+time()
doSomething()
tend+=+time()
difference+=+tend+-+tstart
print("The+doSomething+function+took+{}+seconds+to+execute".format(difference))|code-block|syntax|javascript|1579287|entityMap^0|5|B|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|S|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|N|$]]

You need to use <code>time.time()</code> instead, which outputs unix time with high precision.
Use this code:
<pre><code>from time import time

tstart = time()
doSomething()
tend = time()
difference = tend - tstart
print(&quot;The doSomething function took {} seconds to execute&quot;.format(difference))
</code></pre>

blocks|key|1363930|text|您可以像这样使用timeit来测试一个名为module.py的脚本|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1363931|$+python+-mtimeit+-s+'import+module'|code-block|syntax|javascript|1363932|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

You could use timeit like this to test a script named module.py

<pre><code>$ python -mtimeit -s 'import module'
</code></pre>

blocks|key|1364066|text|start+=+datetime.now()+

#code+for+which+response+time+need+to+be+measured.

end+=+datetime.now()
dif+=+end+-+start
dif_micro+=+dif.microseconds+#+time+in+microseconds
dif_millis+=+dif.microseconds+/+1000+#+time+in+millisseconds|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1364067|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>start = datetime.now() 

#code for which response time need to be measured.

end = datetime.now()
dif = end - start
dif_micro = dif.microseconds # time in microseconds
dif_millis = dif.microseconds / 1000 # time in millisseconds
</code></pre>

blocks|key|1579235|text|如果有人需要这样的东西来分析日志条目之间的延迟，例如...等。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1579236|def+get_time_diff_between_timestruct_tuples(timestruct_tuples):
++++"""
++++expecting+input+like:
++++[(0,+datetime.datetime(2021,+10,+27,+16,+6,+8,+590892)),
++++(1,+datetime.datetime(2021,+10,+27,+16,+6,+8,+591833)),
++++(2,+datetime.datetime(2021,+10,+27,+16,+6,+9,+434053)),
++++(3,+datetime.datetime(2021,+10,+27,+16,+6,+9,+878021)),+...]
++++
++++output+like:
++++[0.941,+0.84222,+0.443968,+...]
++++"""
++++
++++def+seconds_mms_diff(t0,+t1):
++++++++diff+=+t1+-+t0
++++++++s+=+diff.seconds
++++++++mms+=+diff.microseconds
++++++++return+float(f"{s}.{mms}")
++++
++++timediffs+=+[]
++++init+=+timestruct_tuples[0][1]
++++idx+=+0
++++while+idx+<+(len(timestruct_tuples)-1):
++++++++timediffs.append(seconds_mms_diff(init,+timestruct_tuples[idx%2B1][1]))
++++++++idx+%2B=+1
++++++++init+=+timestruct_tuples[idx][1]
++++return+timediffs|code-block|syntax|javascript|1579237|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In case anyone needs something like this to analyze delays between log entries for example ... etc.
<pre><code>def get_time_diff_between_timestruct_tuples(timestruct_tuples):
 &quot;&quot;&quot;
 expecting input like:
 [(0, datetime.datetime(2021, 10, 27, 16, 6, 8, 590892)),
 (1, datetime.datetime(2021, 10, 27, 16, 6, 8, 591833)),
 (2, datetime.datetime(2021, 10, 27, 16, 6, 9, 434053)),
 (3, datetime.datetime(2021, 10, 27, 16, 6, 9, 878021)), ...]
 
 output like:
 [0.941, 0.84222, 0.443968, ...]
 &quot;&quot;&quot;
 
 def seconds_mms_diff(t0, t1):
 diff = t1 - t0
 s = diff.seconds
 mms = diff.microseconds
 return float(f&quot;{s}.{mms}&quot;)
 
 timediffs = []
 init = timestruct_tuples[0][1]
 idx = 0
 while idx &lt; (len(timestruct_tuples)-1):
 timediffs.append(seconds_mms_diff(init, timestruct_tuples[idx+1][1]))
 idx += 1
 init = timestruct_tuples[idx][1]
 return timediffs
</code></pre>

What is the proper way to compare 2 times in Python in order to speed test a section of code? I tried reading the API docs. I'm not sure I understand the timedelta thing.

So far I have this code:

<pre><code>from datetime import datetime

tstart = datetime.now()
print t1

# code to speed test

tend = datetime.now()
print t2
# what am I missing?
# I'd like to print the time diff here
</code></pre>

Python speed testing - Time Difference - milliseconds

Python

Unix

为了加速测试一段代码，在Python中比较2次的正确方法是什么？我试着读了API文档。我不确定我是否理解时间增量的事情。到目前为止，我有以下代码：from datetime import datetimetstart = datetime.now()print t1# code to speed testtend = datetime.now()print t2# what am I missin

问Python速度测试-时间差-毫秒
EN

回答 15

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Python速度测试-时间差-毫秒EN

回答 15

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Python速度测试-时间差-毫秒
EN