大约有 40,000 项符合查询结果（耗时：0.0669秒） [XML]
Build the full path filename in Python
...
This works fine:
os.path.join(dir_name, base_filename + "." + filename_suffix)
Keep in mind that os.path.join() exists only because different operating systems use different path separator characters. It smooths over that difference so cross-platform code d...
Generate a random point within a circle (uniformly)
...m[] 2 Pi;
r = If[u > 1, 2 - u, u];
{r Cos[t], r Sin[t]}
]
ListPlot[Table[f[], {10000}], AspectRatio -> Automatic]
share
|
improve this answer
|
follow
...
Difference between dispatch_async and dispatch_sync on serial queue?
... ensure the serial execution of tasks. The only difference is that dispatch_sync only return after the block is finished whereas dispatch_async return after it is added to the queue and may not finished.
for this code
dispatch_async(_serialQueue, ^{ printf("1"); });
printf("2");
dispatch_async(_se...
How can I visualize per-character differences in a unified diff file?
...ight space changes):
git diff --color-words='[^[:space:]]|([[:alnum:]]|UTF_8_GUARD)+'
In general:
git diff --color-words=<re>
where <re> is a regexp defining "words" for the purpose of identifying changes.
These are less noisy in that they color the changed "words", whereas using ...
OpenSSH升级后不能登录的问题 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...顺利
具体情况这里http://pkgs.org/centos-6/ghettoforge-testing-x86_64/openssh-6.6.1p1-4.gf.el6.x86_64.rpm.html
备份原有源
cd /etc/yum.repos.d/
mv rhel-source.repo rhel-source.repo.bak
mv packagekit-media.repo packagekit-media.repo.bak
配置源
vi CentOS-Base.repo
[base]
name...
Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...lly, setdiff(bigFrame, smallFrame) gets you the extra records in the first table.
In the SQLverse this is called a
For good descriptions of all join options and set subjects, this is one of the best summaries I've seen put together to date: http://www.vertabelo.com/blog/technical-articles/sq...
Difference between \w and \b regular expression meta characters
...ters" are "non-word characters".
In all flavors, the characters [a-zA-Z0-9_] are word characters. These are also matched by the short-hand character class \w. Flavors showing "ascii" for word boundaries in the flavor comparison recognize only these as word characters.
\w stands for "word character...
How do I uniquely identify computers visiting my web site?
...use the following keys on both document.cookie and window.localStorage:
_ga: Google Analytics data
__utma: Google Analytics tracking cookie
sid: SessionID
Make sure you include links to your Privacy policy and terms of use on all pages that use tracking.
Where do I store my session data?
You ...
What is the syntax rule for having trailing commas in tuple definitions?
...
Another reason that this exists is that it makes code generation and __repr__ functions easier to write. For example, if you have some object that is built like obj(arg1, arg2, ..., argn), then you can just write obj.__repr__ as
def __repr__(self):
l = ['obj(']
for arg in obj.args: #...
How do I translate an ISO 8601 datetime string into a Python datetime object? [duplicate]
...EXCEPT for the dash indicating + or - utc offset for the timezone
conformed_timestamp = re.sub(r"[:]|([-](?!((\d{2}[:]\d{2})|(\d{4}))$))", '', timestamp)
datetime.datetime.strptime(conformed_timestamp, "%Y%m%dT%H%M%S.%f%z" )
If your system does not support the %z strptime directive (you see someth...