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What is more efficient: Dictionary TryGetValue or ContainsKey+Item?
...property actually has nearly identical code functionality as TryGetValue, except that it will throw an exception instead of returning false.
Using ContainsKey followed by the Item basically duplicates the lookup functionality, which is the bulk of the computation in this case.
...
Python CSV error: line contains NULL byte
...reported by reader.line_num will be (unhelpfully) 1. Find where the first \x00 is (if any) by doing
data = open('my.csv', 'rb').read()
print data.find('\x00')
and make sure that you dump at least that many bytes with repr or od.
What does data.count('\x00') tell you? If there are many, you may w...
Efficiently convert rows to columns in sql server
...tNumber
from
(
select value, columnname
from yourtable
) d
pivot
(
max(value)
for columnname in (Firstname, Amount, PostalCode, LastName, AccountNumber)
) piv;
See Demo.
Pivot with unknown number of columnnames
If you have an unknown number of columnnames that you want to transpose, then...
How to find out if an installed Eclipse is 32 or 64 bit version?
...pen eclipse.ini in the installation directory, and observe the line with text:
plugins/org.eclipse.equinox.launcher.win32.win32.x86_64_1.0.200.v20090519
then it is 64 bit.
If it would be plugins/org.eclipse.equinox.launcher.win32.win32.x86_32_1.0.200.v20090519 then it is 32 bit.
...
How can I profile C++ code running on Linux?
I have a C++ application, running on Linux, which I'm in the process of optimizing. How can I pinpoint which areas of my code are running slowly?
...
What is the result of % in Python?
...rted to a common type. A zero right argument raises the ZeroDivisionError exception. The arguments may be floating point numbers, e.g., 3.14%0.7 equals 0.34 (since 3.14 equals 4*0.7 + 0.34.) The modulo operator always yields a result with the same sign as its second operand (or zero); the absolute v...
What is the worst real-world macros/pre-processor abuse you've ever come across?
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How do I clear my local working directory in Git? [duplicate]
...ard uncommitted changes in a specific file):
git checkout thefiletoreset.txt
This is mentioned in the git status output:
(use "git checkout -- <file>..." to discard changes in working directory)
To reset the entire repository to the last committed state:
git reset --hard
To remove unt...
Getting All Variables In Scope
...rt("arguments[" + n + "][" + name + "]=" + arg[name]);
}
}
(You can expand on that to get more useful information.)
Instead of that, though, I'd probably use a debugger like Chrome's dev tools (even if you don't normally use Chrome for development) or Firebug (even if you don't normally use F...
`from … import` vs `import .` [duplicate]
... @g.d.d.c: The “single trailing underscore” convention is explicitly specified by PEP 8 (twice). If Eclipse produces annoying warnings about correct code, then we have a bad IDE, not a bad habit.
– wchargin
Feb 16 '18 at 9:11
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