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Renaming columns in pandas
...UMNS
Use the df.rename() function and refer the columns to be renamed. Not all the columns have to be renamed:
df = df.rename(columns={'oldName1': 'newName1', 'oldName2': 'newName2'})
# Or rename the existing DataFrame (rather than creating a copy)
df.rename(columns={'oldName1': 'newName1', 'oldNam...
String concatenation in Ruby
...ficient in term of memory/speed from what I've seen (not measured though). All three methods will throw an uninitialized constant error when ROOT_DIR is nil.
When dealing with pathnames, you may want to use File.join to avoid messing up with pathname separator.
In the end, it is a matter of taste....
How can i query for null values in entity framework?
...g this bug!
For backwards compatibility, it will be opt-in - you need manually enable a setting to make entry == value work. No word yet on what this setting is. Stay tuned!
Edit 2: According to this post by the EF team, this issue has been fixed in EF6! Woohoo!
We changed the default be...
Can a decorator of an instance method access the class?
I have something roughly like the following. Basically I need to access the class of an instance method from a decorator used upon the instance method in its definition.
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Can I have onScrollListener for a ScrollView?
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Every instance of View calls getViewTreeObserver(). Now when holding an instance of ViewTreeObserver, you can add an OnScrollChangedListener() to it using the method addOnScrollChangedListener().
You can see more information about this class here.
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How do you split a list into evenly sized chunks?
...t and empty the second list for the next round of data, but this is potentially extremely expensive.
64 Answers
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Is there a function to make a copy of a PHP array to another?
...ewLarsson raises a point in the comments below. PHP has a special feature called "references". They are somewhat similar to pointers in languages like C/C++, but not quite the same. If your array contains references, then while the array itself is passed by copy, the references will still resolve to...
Are PHP Variables passed by value or by reference?
... function is changed, it does not get changed outside of the function). To allow a function to modify its arguments, they must be passed by reference.
To have an argument to a function always passed by reference, prepend an ampersand (&) to the argument name in the function definition.
&l...
How to color System.out.println output? [duplicate]
...minals simply won't support some (if any) ANSI escape sequences and, especially, 24-bit colors.
Usage
Please refer to the section Curses at the bottom for the best solution. For a personal or easy solution (although not as cross-platform solution), refer to the ANSI Escape Sequences section.
TL...
C dynamically growing array
...ynamic array implementations work by starting off with an array of some (small) default size, then whenever you run out of space when adding a new element, double the size of the array. As you can see in the example below, it's not very difficult at all: (I've omitted safety checks for brevity)
type...