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How to add an empty column to a dataframe?
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463
If I understand correctly, assignment should fill:
>>> import numpy as np
>>>...
How can I convert this foreach code to Parallel.ForEach?
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edited Jul 26 '13 at 9:06
Contango
61.6k5252 gold badges216216 silver badges263263 bronze badges
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Change a column type from Date to DateTime during ROR migration
...ge_date_format_in_my_table
Then in your migration file:
For Rails >= 3.2:
class ChangeDateFormatInMyTable < ActiveRecord::Migration
def up
change_column :my_table, :my_column, :datetime
end
def down
change_column :my_table, :my_column, :date
end
end
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PHP best way to MD5 multi-dimensional array?
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13 Answers
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【BLE技术内幕】BLE技术揭秘 - 创客硬件开发 - 清泛IT论坛，有思想、有深度
...uetooth SIG）在2010年发布了跨时代的蓝牙4.0，它并不是蓝牙3.0的简单升级版本，而是全新的技术架构，蓝牙4.0版本分两种模式：单模蓝牙和双模蓝牙。常见的蓝牙音箱，是典型的双模蓝牙，它需要传输大量的音频数据。而小米手环...
Python loop that also accesses previous and next values
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edited Apr 27 '16 at 13:32
Trang Oul
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answered Jun 18 '09 at 10:28
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Drop rows with all zeros in pandas data frame
...0,1,0,1]})
> df = df[(df.T != 0).any()]
> df
a b
1 0 1
2 1 0
3 1 1
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Changing the color of the axis, ticks and labels for a plot in matplotlib
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3 Answers
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How to use timeit module
...int min(timeit.Timer('a=s[:]; timsort(a)', setup=setup).repeat(7, 1000))
0.334147930145
Note that the series of statements makes a fresh copy of the unsorted data on every pass.
Also, note the timing technique of running the measurement suite seven times and keeping only the best time -- this can...