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ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)
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18 Answers
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Relative frequencies / proportions with dplyr
...se(n = n()) %>%
mutate(freq = n / sum(n))
# am gear n freq
# 1 0 3 15 0.7894737
# 2 0 4 4 0.2105263
# 3 1 4 8 0.6153846
# 4 1 5 5 0.3846154
From the dplyr vignette:
When you group by multiple variables, each summary peels off one level of the grouping. That mak...
How to sort a list in Scala by two fields?
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217
rows.sortBy(r => (r.lastName, r.firstName))
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Static variables in member functions
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169
Since class A is a non-template class and A::foo() is a non-template function. There will be o...
The modulo operation on negative numbers in Python
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134
Unlike C or C++, Python's modulo operator (%) always return a number having the same sign as t...
How can I make pandas dataframe column headers all lowercase?
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180
You can do it like this:
data.columns = map(str.lower, data.columns)
or
data.columns = [x....
OAuth: how to test with local URLs?
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139
Update October 2016: Easiest now: use lvh.me which always points to 127.0.0.1.
Previous Answer...
Regex how to match an optional character
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Use
[A-Z]?
to make the letter optional. {1} is redundant. (Of course you could also write [A-Z]{0,1} which would mean the same, but that's what the ? is there for.)
You could improve your regex to
^([0-9]{5})+\s+([A-Z]?)\s+([A-Z])([0-9]{3})([0-9]{3})([A-Z]{3})([A-...
How to remove the querystring and get only the url?
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16 Answers
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How to add a spinner icon to button when it's in the Loading state?
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101
If you look at the bootstrap-button.js source, you'll see that the bootstrap plugin replaces t...