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What is the difference between map and flatMap and a good use case for each?
...ark-shell session:
First, some data - two lines of text:
val rdd = sc.parallelize(Seq("Roses are red", "Violets are blue")) // lines
rdd.collect
res0: Array[String] = Array("Roses are red", "Violets are blue")
Now, map transforms an RDD of length N into another RDD of length N.
For examp...
Can you get the column names from a SqlDataReader?
After connecting to the database, can I get the name of all the columns that were returned in my SqlDataReader ?
9 Answers...
How do I use itertools.groupby()?
I haven't been able to find an understandable explanation of how to actually use Python's itertools.groupby() function. What I'm trying to do is this:
...
Nested attributes unpermitted parameters
... Person . I want a form that can create the Bill and its children Dues all in one page. I am trying to create a form using nested attributes, similar to ones in this Railscast .
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Python Infinity - Any caveats?
...involving inf:
>>> 0 * float("inf")
nan
Note that you will normally not get an inf value through usual arithmetic calculations:
>>> 2.0**2
4.0
>>> _**2
16.0
>>> _**2
256.0
>>> _**2
65536.0
>>> _**2
4294967296.0
>>> _**2
1.84467440737...
vagrant up failed, /dev/vboxnetctl: no such file or directory
Can be useful, I found this error. The common solution is reinstall virtualbox but there are a better way.
8 Answers
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python setup.py uninstall
I have installed a python package with python setup.py install .
16 Answers
16
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How do you use “git --bare init” repository?
...ush) from another repository.
Note that in this case you'll need to first allow people to push to your repository. When inside test_repo.git, do
git config receive.denyCurrentBranch ignore
Community edit
git init --bare --shared=group
As commented by prasanthv, this is what you want if you ar...
How to redirect output to a file and stdout
In bash, calling foo would display any output from that command on the stdout.
10 Answers
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Android Task Affinity Explanation
...ayer stack of activities, and two of them were the same activity. Popping all 5 off the stack will create the phenomenon where you will be interacting with two different versions of the same activity and can be quite confusing.
Users don't usually think in terms of a rigid stack of activities. ...