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What is NODE_ENV and how to use it in Express?
...ment variable and do different things based on the value. NODE_ENV specifically is used (by convention) to state whether a particular environment is a production or a development environment. A common use-case is running additional debugging or logging code if running in a development environment.
A...
Android: Specify two different images for togglebutton using XML
...d come last. Arrange the items in the following manner to ensure they will all be utilized:
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:state_checked="true" android:state_pressed="true" /> //currently pressed turning the toggle on
<item...
Canary release strategy vs. Blue/Green
...old until someone flips a feature toggle. Breaking your application into small, independently releaseable services is another, since there is less to test and less that can break.
You need to do a canary release if you're not completely certain that the new version will function correctly in produc...
How to check if a column exists in Pandas
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To check if one or more columns all exist, you can use set.issubset, as in:
if set(['A','C']).issubset(df.columns):
df['sum'] = df['A'] + df['C']
As @brianpck points out in a comment, set([]) can alternatively be constructed with curly...
Can a class member function template be virtual?
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Templates are all about the compiler generating code at compile-time. Virtual functions are all about the run-time system figuring out which function to call at run-time.
Once the run-time system figured out it would need to call a templ...
Variable declaration placement in C
I long thought that in C, all variables had to be declared at the beginning of the function. I know that in C99, the rules are the same as in C++, but what are the variable declaration placement rules for C89/ANSI C?
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Are std::vector elements guaranteed to be contiguous?
...e in the middle take linear time. Storage
management is handled automatically, though hints can be given to improve efficiency. The elements of a
vector are stored contiguously, meaning that if v is a vector where T is some type other
than bool, then it obeys the identity &v[n] == &v[0...
Python Regex instantly replace groups
Is there any way to directly replace all groups using regex syntax?
2 Answers
2
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Which parts of Real World Haskell are now obsolete or considered bad practice?
...move return from Monad, so the Monad instance in Real World Haskell will really be out of sync with the real world.
That being said, it's still a useful resource for general guidelines. But keep in mind that many libraries changed since its release.
Something you can read along while reading RWH i...
How ListView's recycling mechanism works
So I have this problem I had before, and naturally I asked for help on here . Luksprog's answer was great because I had no idea about how ListView and GridView optimized itself with recycling Views. So with his advice I was able to change how I added Views to my GridView. Problem is now I have some...