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Determine what attributes were changed in Rails after_save callback?
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Just to be clear: in my tests (Rails 4), if you are using an after_save callback, self.changed? is true and self.attribute_name_changed? is also true, but self.previous_changes returns an empty hash.
– sandre89
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Parsing Visual Studio Solution files
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On the solution file I tested on, this slntools actually gave more details than the ReSharper libs.
– Răzvan Flavius Panda
Nov 20 '14 at 9:02
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How to apply a function to two columns of Pandas dataframe
...s to be taken around datatypes.
In your example, you would (as I did when testing the answer) naively call
df['col_3'] = df.col_1.combine(df.col_2, func=get_sublist)
However, this throws the error:
ValueError: setting an array element with a sequence.
My best guess is that it seems to expec...
Class vs. static method in JavaScript
... this.element.style.color = "red";
}
};
And to use it:
Foo.Talk("Testing");
Or
Foo.ChangeElement();
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How do I replace NA values with zeros in an R dataframe?
...ults.
If you are struggling with massive dataframes, data.table is the fastest option of all: 40% faster than the standard Base R approach. It also modifies the data in place, effectively allowing you to work with nearly twice as much of the data at once.
A clustering of other helpful tidyverse ...
How do I count the number of occurrences of a char in a String?
...r answer and what I know all ways to do this using a one-liner:
String testString = "a.b.c.d";
1) Using Apache Commons
int apache = StringUtils.countMatches(testString, ".");
System.out.println("apache = " + apache);
2) Using Spring Framework's
int spring = org.springframework.util.StringU...
PHP array delete by value (not key)
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@Adam Why not test it out? My feeling is that array_diff() would be slower as it's comparing two arrays, not simply searching through one like array_search().
– Bojangles
Aug 29 '11 at 0:57
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How can I reference a commit in an issue comment on GitHub?
...commit is in the repo named dev, and the GitLab issue is in the repo named test. You can leave a comment on the issue and reference the commit by dev@e9c11f0a (where e9c11f0a is the first 8 letters of the sha hash of the commit you want to link to) if that makes sense.
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How do I get a UTC Timestamp in JavaScript?
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I test the following codes: var tt = new Date('Thu Jan 01 1970 08:00:00 GMT+0800 (China Standard Time)'); (tt.getTime() - tt.getTimezoneOffset()*60*1000)/1000. It seems tt.getTime() - tt.getTimezoneOffset() is correct for GMT+0...
How to “inverse match” with regex?
...e it is written in, but worked like a charm in Sublime text to clean up my test data. Thanks!
– Matthias dirickx
May 4 '17 at 11:21
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