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In Python, what is the difference between “.append()” and “+= []”?
...d will add one item to the list, while += will copy all elements of right-hand-side list into the left-hand-side list.
Update: perf analysis
Comparing bytecodes we can assume that append version wastes cycles in LOAD_ATTR + CALL_FUNCTION, and += version -- in BUILD_LIST. Apparently BUILD_LIST outw...
MySQL, Check if a column exists in a table with SQL
... query that will check if a specific table in MySQL has a specific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception.
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How to capitalize the first character of each word in a string
...t into Java that capitalizes the first character of each word in a String, and does not affect the others?
51 Answers
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How does the const constructor actually work?
...calized" instance.
That is, all constant expressions begin canonicalized, and later these "canonicalized" symbols are used to recognize equivalence of these constants.
Canonicalization:
A process for converting data that has more than one possible representation into a "standard" canonical repres...
Bash script to calculate time elapsed
...a script in bash to calculate the time elapsed for the execution of my commands, consider:
10 Answers
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Haskell testing workflow
I just started a new Haskell project and wanted to set up a good testing workflow from the beginning. It seems like Haskell has a lot of excellent and unique testing tools and many different ways to integrate them.
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Automatically update version number
... in" stuff, you can't, as using 1.0.* or 1.0.0.* will replace the revision and build numbers with a coded date/timestamp, which is usually also a good way.
For more info, see the Assembly Linker Documentation in the /v tag.
As for automatically incrementing numbers, use the AssemblyInfo Task:
As...
How to make CSS3 rounded corners hide overflow in Chrome/Opera
...w: hidden works in simple situations, but breaks in webkit based browsers and Opera when the parent is positioned relatively or absolutely.
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How can I split and parse a string in Python?
...a fact that the string contains an underscore, you can even unpack the LHS and RHS into separate variables:
In [8]: lhs, rhs = "2.7.0_bf4fda703454".split("_", 1)
In [9]: lhs
Out[9]: '2.7.0'
In [10]: rhs
Out[10]: 'bf4fda703454'
An alternative is to use partition(). The usage is similar to the la...
Differences in boolean operators: & vs && and | vs ||
I know the rules for && and || but what are & and | ? Please explain these to me with an example.
11 Ans...