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how to concatenate two dictionaries to create a new one in Python? [duplicate]
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Slowest and doesn't work in Python3: concatenate the items and call dict on the resulting list:
$ python -mtimeit -s'd1={1:2,3:4}; d2={5:6,7:9}; d3={10:8,13:22}' \
'd4 = dict(d1.items() + d2.items() + d3.items())'
100000 loops, bes...
Generating a random & unique 8 character string using MySQL
...nsists of two very different sub-problems:
the string must be seemingly random
the string must be unique
While randomness is quite easily achieved, the uniqueness without a retry loop is not. This brings us to concentrate on the uniqueness first. Non-random uniqueness can trivially be achieved w...
Android: When is onCreateOptionsMenu called during Activity lifecycle?
I put a couple of breakpoints in onCreate (one at the beginning, and one at the end of the method), and I also put one at the beginning of onCreateOptionsMenu . The onCreate method is called first, and before it finishes onCreateOptionsMenu is called.
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How to add /usr/local/bin in $PATH on Mac
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One note: you don't need quotation marks here because it's on the right hand side of an assignment, but in general, and especially on Macs with their tradition of spacy pathnames, expansions like $PATH should be double-quoted as "$PATH".
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Remove duplicated rows using dplyr
...mple(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_number(z) == 1)
## Source: local data frame [3 x 3]
## Groups: x, y
##
## x y z
## 1 0 1 1
## 2 1 0 2
## 3 1 1 4
(In dplyr 0.2 you won't need...
How do you Force Garbage Collection from the Shell?
So I am looking at a heap with jmap on a remote box and I want to force garbage collection on it. How do you do this without popping into jvisualvm or jconsole and friends?
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Path to MSBuild
...\MSBuild\ToolsVersions\4.0
may be what you're after; fire up regedit.exe and have a look.
Query via command line (per Nikolay Botev)
reg.exe query "HKLM\SOFTWARE\Microsoft\MSBuild\ToolsVersions\4.0" /v MSBuildToolsPath
Query via PowerShell (per MovGP0)
dir HKLM:\SOFTWARE\Microsoft\MSBuild\Too...
optional parameters in SQL Server stored proc?
I'm writing some stored procs in SQL Server 2008, and wondered if the concept of optional input parameters is possible here?
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Is the safe-bool idiom obsolete in C++11?
This answer of @R. Martinho Fernandes shows, that the safe-bool idiom is apperently deprecated in C++11, as it can be replaced by a simple
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Fixed Table Cell Width
... the table-layout:fixed style on the <table> or the tables css class and set the overflow style for the cells
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/col
<table class="fixed">
<col width="20px" />
<col width="30px" />
<col width="40px" />...