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Active Record - Find records which were created_at before today
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Using ActiveRecord the standard way:
MyModel.where("created_at < ?", 2.days.ago)
Using the underlying Arel interface:
MyModel.where(MyModel.arel_table[:created_at].lt(2.days.ago))
Using a thin layer over Arel:
MyModel.where(MyModel[:created_at] < 2.days.ago)
Using squeel:
MyModel.w...
How to pad zeroes to a string?
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2506
Strings:
>>> n = '4'
>>> print(n.zfill(3))
004
And for numbers:
>>...
How do I merge a list of dicts into a single dict?
... d in L:
... result.update(d)
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>>> result
{'a':1,'c':1,'b':2,'d':2}
As a comprehension:
# Python >= 2.7
{k: v for d in L for k, v in d.items()}
# Python < 2.7
dict(pair for d in L for pair in d.items())
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App Inventor 2 上传文件和图片到服务器教程 · App Inventor 2 中文网
...生成 App 鸿蒙 · 一套积木，多端原生打包！ 下载 AI2伴侣 · 安卓/鸿蒙/iOS aia 源码商店 中文社区 中文教育版 各版本对比 关于 关于我们 发布日志 服务条款 ...
How to change the output color of echo in Linux
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2435
You can use these ANSI escape codes:
Black 0;30 Dark Gray 1;30
Red 0...
How can I verify if one list is a subset of another?
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Boris
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answered May 16 '13 at 4:59
Yann VernierYann Vern...
PHP Foreach Pass by Reference: Last Element Duplicating? (Bug?)
... $item is still a reference to some value which is also being used by $arr[2]. So each foreach call in the second loop, which does not call by reference, replaces that value, and thus $arr[2], with the new value.
So loop 1, the value and $arr[2] become $arr[0], which is 'foo'.
Loop 2, the value and ...
Truncate number to two decimal places without rounding
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How do I delete rows in a data frame?
...he '-' operator.
So, assuming the data.frame is called myData:
myData[-c(2, 4, 6), ] # notice the -
Of course, don't forget to "reassign" myData if you wanted to drop those rows entirely---otherwise, R just prints the results.
myData <- myData[-c(2, 4, 6), ]
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App Inventor 俄罗斯方块：画布实现的完整小游戏（附 .aia 源码） · App Inventor 2 中文网
...生成 App 鸿蒙 · 一套积木，多端原生打包！ 下载 AI2伴侣 · 安卓/鸿蒙/iOS aia 源码商店 中文社区 中文教育版 各版本对比 关于 关于我们 发布日志 服务条款 ...