大约有 40,000 项符合查询结果（耗时：0.0622秒） [XML]
rgdal package installation
...liam Kyngesburye at http://www.kyngchaos.com/ may be used for
source installs on OSX.
As you seem to be under Linux, you always build package from source, so you will have to install the corresponding libraries on your system. If you are under Mint, Ubuntu or another Debian derivative, you can d...
Representing graphs (data structure) in Python
...f._graph[node2].add(node1)
def remove(self, node):
""" Remove all references to node """
for n, cxns in self._graph.items(): # python3: items(); python2: iteritems()
try:
cxns.remove(node)
except KeyError:
pass
tr...
How to serve an image using nodejs
...
2016 Update
Examples with Express and without Express that actually work
This question is over 5 years old but every answer has some problems.
TL;DR
Scroll down for examples to serve an image with:
express.static
express
connect
http
net
All of the examples are also on GitHub: htt...
Is it possible to run a single test in MiniTest?
I can run all tests in a single file with:
13 Answers
13
...
When I catch an exception, how do I get the type, file, and line number?
...Error:
print(traceback.format_exc())
Output
Traceback (most recent call last):
File "/path/to/file.py", line 51, in <module>
print(4/0)
ZeroDivisionError: division by zero
Process finished with exit code 0
...
Django select only rows with duplicate field values
... syntax is also how Django interprets you wanting to do a join. So, essentially when you try to filter on that, Django thinks you're trying to do a join with count which obviously doesn't exist. The fix is to specify a name for your annotation result, i.e. annotate(mycount=Count('id')) and then filt...
How to make a class JSON serializable
...t;>> magic(f)
'{"fname": "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONE...
Can I install Python windows packages into virtualenvs?
Virtualenv is great: it lets me keep a number of distinct Python installations so that different projects' dependencies aren't all thrown together into a common pile.
...
Does use of final keyword in Java improve the performance?
...
Usually not. For virtual methods, HotSpot keeps track of whether the method has actually been overridden, and is able to perform optimizations such as inlining on the assumption that a method hasn't been overridden - until it lo...
What are some uses of template template parameters?
...alue) {
}
Here, H is a template, but I wanted this function to deal with all specializations of H.
NOTE: I've been programming c++ for many years and have only needed this once. I find that it is a rarely needed feature (of course handy when you need it!).
I've been trying to think of good examp...