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List comprehension vs map
... map when using exactly the same function:
$ python -mtimeit -s'xs=range(10)' 'map(hex, xs)'
100000 loops, best of 3: 4.86 usec per loop
$ python -mtimeit -s'xs=range(10)' '[hex(x) for x in xs]'
100000 loops, best of 3: 5.58 usec per loop
An example of how performance comparison gets completely r...
How to tell if a tag failed to load
...d I'd like to be able to tell whether the loading failed in some way -- a 404, a script error in the loaded script, whatever.
...
How to sort an array by a date property
... else if(sort_o1_after_o2) return 1;
else return 0;
});
Or more tersely:
array.sort(function(o1,o2){
return sort_o1_before_o2 ? -1 : sort_o1_after_o2 ? 1 : 0;
});
Generic, Powerful Answer
Define a custom non-enumerable sortBy function using a Schwartzian transform o...
Format / Suppress Scientific Notation from Python Pandas Aggregation Results
...float_format', lambda x: '%.3f' % x)
In [28]: Series(np.random.randn(3))*1000000000
Out[28]:
0 -757322420.605
1 -1436160588.997
2 -1235116117.064
dtype: float64
I'm not sure if that's the preferred way to do this, but it works.
Converting numbers to strings purely for aesthetic purposes ...
Convert JS date time to MySQL datetime
...nction to pad numbers to two digits…
**/
function twoDigits(d) {
if(0 <= d && d < 10) return "0" + d.toString();
if(-10 < d && d < 0) return "-0" + (-1*d).toString();
return d.toString();
}
/**
* …and then create the method to output the date string as ...
Removing a list of characters in string
...e) == test
t = timeit.timeit(lambda: f(subj, chars_to_remove), number=1000)
print ('{0:.3f} {1}'.format(t, f.__name__))
print (sys.version)
PYTHON2 = sys.version_info[0] == 2
print ('\n"plain" string:\n')
chars_to_remove = ['.', '!', '?']
subj = 'A.B!C?' * 1000
test = 'ABC' * 1000
profil...
Are the shift operators () arithmetic or logical in C?
...
Basically you need to either test your compiler or not rely on it. My VS2008 help for the current MS C++ compiler says that their compiler does an arithmetic shift.
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...
List All Redis Databases
...the databases for which some keys are defined:
INFO keyspace
# Keyspace
db0:keys=10,expires=0
db1:keys=1,expires=0
db3:keys=1,expires=0
Please note that you are supposed to use the "redis-cli" client to run these commands, not telnet. If you want to use telnet, then you need to run these commands...
python pandas: apply a function with arguments to a series
...
170
Newer versions of pandas do allow you to pass extra arguments (see the new documentation). So no...
Controlling maven final name of jar artifact
...
303
You set the finalName property in the plugin configuration section:
<plugin>
<gro...