大约有 48,000 项符合查询结果（耗时：0.0417秒） [XML]
Applying a function to every row of a table using dplyr?
...
202
As of dplyr 0.2 (I think) rowwise() is implemented, so the answer to this problem becomes:
ir...
If vs. Switch Speed
...
answered Jan 14 '09 at 23:16
Konrad RudolphKonrad Rudolph
461k118118 gold badges863863 silver badges11101110 bronze badges
...
How to not run an example using roxygen2?
...
answered Aug 20 '12 at 13:03
GSeeGSee
43.4k1111 gold badges108108 silver badges134134 bronze badges
...
How to assert two list contain the same elements in Python? [duplicate]
...
As of Python 3.2 unittest.TestCase.assertItemsEqual(doc) has been replaced by unittest.TestCase.assertCountEqual(doc) which does exactly what you are looking for, as you can read from the python standard library documentation. The method is...
Which one will execute faster, if (flag==0) or if (0==flag)?
...
236
I haven't seen any correct answer yet (and there are already some) caveat: Nawaz did point out...
Add 2 hours to current time in MySQL?
...
SELECT *
FROM courses
WHERE DATE_ADD(NOW(), INTERVAL 2 HOUR) > start_time
See Date and Time Functions for other date/time manipulation.
share
|
improve this answer
...
Creating a new column based on if-elif-else condition
... passing in the axis=1 option:
In [1]: df['C'] = df.apply(f, axis=1)
In [2]: df
Out[2]:
A B C
a 2 2 0
b 3 1 1
c 1 3 -1
Of course, this is not vectorized so performance may not be as good when scaled to a large number of records. Still, I think it is much more readable. Especially c...
What is non-blocking or asynchronous I/O in Node.js?
...
2 Answers
2
Active
...
How to overcome TypeError: unhashable type: 'list'
...pend(value)
else:
d[key] = [value]
print d
# {'AAA': ['111', '112'], 'AAC': ['123'], 'AAB': ['111']}
Note that if you are using Python 3.x, you'll have to make a minor adjustment to get it work properly. If you open the file with rb, you'll need to use line = line.split(b'x') (which mak...
Mapping two integers to one, in a unique and deterministic way
...
234
You're looking for a bijective NxN -> N mapping. These are used for e.g. dovetailing. Have ...