大约有 30,000 项符合查询结果（耗时：0.0562秒） [XML]
python date of the previous month
...
datetime and the datetime.timedelta classes are your friend.
find today.
use that to find the first day of this month.
use timedelta to backup a single day, to the last day of the previous month.
print the YYYYMM string you're ...
How to avoid explicit 'self' in Python?
...riants of "you can't" or "you shouldn't". While I agree with the latter sentiment, the question is technically still unanswered.
Furthermore, there are legitimate reasons why someone might want to do something along the lines of what the actual question is asking. One thing I run into sometimes is...
How to validate IP address in Python? [duplicate]
...sible leading 0's)
)
(?: # Repeat 0-3 times, separated by a dot
\.
(?:
[3-9]\d?|2(?:5[0-5]|[0-4]?\d)?|1\d{0,2}
|
0x0*[0-9a-f]{1,2}
|
0+[1-3]?[0-7]{0,2}
)
...
Weighted random numbers
... and is less than the sum of the weights
3) go through the items one at a time, subtracting their weight from your random number, until you get the item where the random number is less than that item's weight
Pseudo-code illustrating this:
int sum_of_weight = 0;
for(int i=0; i<num_choices; i++...
Python Image Library fails with message “decoder JPEG not available” - PIL
...ilations. Certainly, it was a very lengthy to pip install things the first time, but then subsequent uninstalls and (re)installs were suspiciously quick. Anyway, the methods above did not work for me until I ran pip install --no-cache-dir pillow. Good luck!
– t-mart
...
Determining Whether a Directory is Writeable
...ier to ask for forgiveness" is not the best way, even in Python. It is sometimes advisable to "ask permission" as with the os.access() method mentioned, for example when the probability of having to catch an error is high.
– mjv
Feb 6 '10 at 19:32
...
How can I randomize the lines in a file using standard tools on Red Hat Linux?
...k, but it doesn't. It still displays the shuffled file to stdout, but this time it deletes the original. I suggest you don't use it.
Consider a shell script:
#!/bin/sh
if [[ $# -eq 0 ]]
then
echo "Usage: $0 [file ...]"
exit 1
fi
for i in "$@"
do
perl -MList::Util -e 'print List::Util::shuf...
Generate random numbers with a given (numerical) distribution
...
On my machine numpy.random.choice() is almost 20 times faster.
– Eugene Pakhomov
Jun 18 '16 at 6:26
9
...
Is there a link to GitHub for downloading a file in the latest release of a repository?
...k to download a specific version of the published software. However, every time a release is made, the gh-page also needs to be updated.
...
Serializing class instance to JSON
... serial = obj.isoformat()
return serial
if isinstance(obj, time):
serial = obj.isoformat()
return serial
return obj.__dict__
First two ifs are for date and time serialization
and then there is a obj.__dict__ returned for any other object.
the final call looks ...