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count the frequency that a value occurs in a dataframe column
...columns you can use:
df.apply(pd.value_counts)
This will apply a column based aggregation function (in this case value_counts) to each of the columns.
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What is the meaning of the 'g' flag in regular expressions?
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Will give example based on string. If we want to remove all occurences from a
string.
Lets say if we want to remove all occurences of "o" with "" from "hello world"
"hello world".replace(/o/g,'');
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How to check if a DateTime occurs today?
...s a DateTime object
.NET is smart enough to determine you want to compare based on Date only and uses that for the internal Compare. Not sure why, and actually having trouble finding documentation for this behaviour.
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Extract a regular expression match
...nces in 'See also':
‘regmatches’ for extracting matched substrings based on the results of
‘regexpr’, ‘gregexpr’ and ‘regexec’.
So this will work, and is fairly simple:
txt <- "aaa12xxx"
regmatches(txt,regexpr("[0-9]+",txt))
#[1] "12"
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How to view DLL functions?
...tBrains.
https://www.jetbrains.com/decompiler/
dotPeek is a free tool based on ReSharper. It can reliably decompile
any .NET assembly into C# or IL code.
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Cannot lower case button text in android studio
...forementioned attribute. Here's what it had <resources> <!-- Base application theme. --> <style name="AppTheme" parent="android:Theme.Holo.Light.DarkActionBar"> <!-- Customize your theme here. --> </style> </resources>
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Parameterize an SQL IN clause
... not open to SQL injection. The only injected text into CommandText is not based on user input. It's solely based on the hardcoded "@tag" prefix, and the index of an array. The index will always be an integer, is not user generated, and is safe.
The user inputted values are still stuffed into param...
Git - Difference Between 'assume-unchanged' and 'skip-worktree'
...cally.
That last part is what I describe a typical content filter driver based on smudge/clean scripts.
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Opposite of %in%: exclude rows with values specified in a vector
...ages/purrr/versions/0.2.5/topics/… stat.ethz.ch/R-manual/R-devel/library/base/html/match.fun.html
– flying sheep
Mar 15 '19 at 16:44
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What's the difference(s) between .ToList(), .AsEnumerable(), AsQueryable()?
...here that would be useful. As I explained, applying AsQueryable() is often based on misconception. But I'll let is simmer in the back of my head for a while and see if I can add some more coverage on that question.
– Gert Arnold
Aug 29 '19 at 11:16
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