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Nested defaultdict of defaultdict
...
For an arbitrary number of levels:
def rec_dd():
return defaultdict(rec_dd)
>>> x = rec_dd()
>>> x['a']['b']['c']['d']
defaultdict(<function rec_dd at 0x7f0dcef81500>, {})
>>> print json.dumps(x)
{"a": {"b": {"c": {"d": {}}}}}
...
clang: how to list supported target architectures?
...e triples requires solving the Halting Problem. See, for example, llvm::ARM_MC::ParseARMTriple(...) which special-cases parsing the string "generic".
Ultimately, though, the "triple" is mostly a backwards-compatibility feature to make Clang a drop-in replacement for GCC, so you generally don't need...
Linux command or script counting duplicated lines in a text file?
...3
}
or you can use a simple one-liner:
$ cat filename | python3 -c 'print(__import__("json").dumps(__import__("collections").Counter(map(str.strip, __import__("fileinput").input())), indent=2))'
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...
MongoDB SELECT COUNT GROUP BY
...ier way to do it using aggregate:
db.contest.aggregate([
{"$group" : {_id:"$province", count:{$sum:1}}}
])
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...
Updating MySQL primary key
I have a table user_interactions with 4 columns:
3 Answers
3
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What is the Python equivalent of Matlab's tic and toc functions?
...) - t
I have a helper class I like to use:
class Timer(object):
def __init__(self, name=None):
self.name = name
def __enter__(self):
self.tstart = time.time()
def __exit__(self, type, value, traceback):
if self.name:
print('[%s]' % self.name,)
...
clang error: unknown argument: '-mno-fused-madd' (python package installation failure)
...s/2.7/include/python2.7 -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -mno-fused-madd -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DT...
How do I search for an object by its ObjectId in the mongo console?
...est.find() // no criteria
{ "_id" : ObjectId("4ecc05e55dd98a436ddcc47c"), "x" : 1 }
> db.test.find({"_id" : ObjectId("4ecc05e55dd98a436ddcc47c")}) // explicit
{ "_id" : ObjectId("4ecc05e55dd98a436ddcc47c"), "x" : 1 }
> db.test.find(ObjectId...
open read and close a file in 1 line of code
...athlib module does what you looking for:
Path('pagehead.section.htm').read_text()
Don't forget to import Path:
jsk@dev1:~$ python3
Python 3.5.2 (default, Sep 10 2016, 08:21:44)
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from ...
mongodb count num of distinct values per field/key
...}
},
{ $unwind: "$keywords" },
{
$group: {
_id: {$toLower: '$keywords'},
count: { $sum: 1 }
}
},
{
$match: {
count: { $gte: 2 }
}
},
{ $sort : { count : -1} },
{ $limit : 100 }
]);
that give result ...