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Is there a way to 'uniq' by column?
...o you need the ,1 in -k1,1? why not just -k1?
– hello_there_andy
Nov 24 '14 at 20:10
19
@hello_th...
Count, size, length…too many choices in Ruby?
...1
In the case where you don't provide a parameter to count it has basically the same effect as calling length. There can be a performance difference though.
We can see from the source code for Array that they do almost exactly the same thing. Here is the C code for the implementation of array.l...
Declaration/definition of variables locations in ObjectiveC?
Ever since starting to work on iOS apps and objective C I've been really puzzled by the different locations where one could be declaring and defining variables. On one hand we have the traditional C approach, on the other we have the new ObjectiveC directives that add OO on top of that. Could you fo...
How do I create an immutable Class?
I am working on creating an immutable class.
I have marked all the properties as read-only.
6 Answers
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What is the difference between the Data Mapper, Table Data Gateway (Gateway), Data Access Object (DA
... skills, and I'm curious what are the differences between these patterns? All of them seem like they are the same thing - encapsulate the database logic for a specific entity so the calling code has no knowledge of the underlying persistence layer. From my brief research all of them typically impl...
How do I trim leading/trailing whitespace in a standard way?
... C? I'd roll my own, but I would think this is a common problem with an equally common solution.
38 Answers
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How can I output leading zeros in Ruby?
...counter is known (e.g., n = 3 for counters 1..876), you can do
str = "file_" + i.to_s.rjust(n, "0")
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How to get the last N rows of a pandas DataFrame?
... dataframe df1 and df2 (df1 is vanila dataframe, df2 is indexed by 'STK_ID' & 'RPT_Date') :
3 Answers
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How do I find out what keystore my JVM is using?
...
Your keystore will be in your JAVA_HOME---> JRE -->lib---> security--> cacerts. You need to check where your JAVA_HOME is configured, possibly one of these places,
Computer--->Advanced --> Environment variables---> JAVA_HOME
Your serv...
Preloading CSS Images
...ly elements guaranteed to exist on the page.
For the "trick" to work, we shall use the content property which comfortably allows setting multiple URLs to be loaded, but as shown, the ::after pseudo element is kept hidden so the images won't be rendered:
body::after{
position:absolute; width:0; he...