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Convert columns to string in Pandas
...n (and therefore your keys to strings):
In [11]: df = pd.DataFrame([['A', 2], ['A', 4], ['B', 6]])
In [12]: df.to_json()
Out[12]: '{"0":{"0":"A","1":"A","2":"B"},"1":{"0":2,"1":4,"2":6}}'
In [13]: df[0].to_json()
Out[13]: '{"0":"A","1":"A","2":"B"}'
Note: you can pass in a buffer/file to save t...
Java synchronized static methods: lock on object or class
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129
Since a static method has no associated object, will the synchronized keyword lock on the c...
Why should I use Deque over Stack?
...tack<Integer> stack = new Stack<>();
stack.push(1);
stack.push(2);
stack.push(3);
System.out.println(new ArrayList<>(stack)); // prints 1, 2, 3
Deque<Integer> deque = new ArrayDeque<>();
deque.push(1);
deque.push(2);
deque.push(3);
System.out.println(new ArrayList<...
Appending an element to the end of a list in Scala
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List(1,2,3) :+ 4
Results in List[Int] = List(1, 2, 3, 4)
Note that this operation has a complexity of O(n). If you need this operation frequently, or for long lists, consider using another data type (e.g. a ListBuffer).
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How to suppress Update Links warning?
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UPDATE:
After all the details summarized and discussed, I spent 2 fair hours in checking the options, and this update is to dot all is.
Preparations
First of all, I performed a clean Office 2010 x86 install on Clean Win7 SP1 Ultimate x64 virtual machine powered by VMWare (this is usual ...
Python mysqldb: Library not loaded: libmysqlclient.18.dylib
I just compiled and installed mysqldb for python 2.7 on my mac os 10.6. I created a simple test file that imports
15 Answe...
Moment.js: Date between dates
... detect with Moment.js if a given date is between two dates. Since version 2.0.0, Tim added isBefore() and isAfter() for date comparison.
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Python: Find in list
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1235
As for your first question: that code is perfectly fine and should work if item equals one of ...
Approximate cost to access various caches and main memory?
Can anyone give me the approximate time (in nanoseconds) to access L1, L2 and L3 caches, as well as main memory on Intel i7 processors?
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