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python tuple to dict
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Try:
>>> t = ((1, 'a'),(2, 'b'))
>>> dict((y, x) for x, y in t)
{'a': 1, 'b': 2}
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Remove duplicates in the list using linq
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var distinctItems = items.Distinct();
To match on only some of the properties, create a custom equality comparer, e.g.:
class DistinctItemComparer : IEqualityComparer<Item> {
public bool Equals(Item x, Item y) {
return x.Id == y.Id &&
x.N...
How to sort a dataframe by multiple column(s)
I want to sort a data.frame by multiple columns. For example, with the data.frame below I would like to sort by column z (descending) then by column b (ascending):
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How to change the opacity (alpha, transparency) of an element in a canvas element after it has been
...ke to load an image file (PNG, JPEG, etc.), draw it to the canvas completely transparently, and then fade it in. I have figured out how to load the image and draw it to the canvas, but I don't know how to change its opacity once it as been drawn.
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How can I convert a long to int in Java?
...Updated, in Java 8:
Math.toIntExact(value);
Original Answer:
Simple type casting should do it:
long l = 100000;
int i = (int) l;
Note, however, that large numbers (usually larger than 2147483647 and smaller than -2147483648) will lose some of the bits and would be represented incorrectly.
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How to change line width in ggplot?
...hin aes(...) is mapped from the data, and a legend created.
An aesthetic may also be set to a single value, by defining it outside aes().
As far as I can tell, what you want is to set size to a single value, not map within the call to aes()
When you call aes(size = 2) it creates a variable called...
How to avoid having class data shared among instances?
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You want this:
class a:
def __init__(self):
self.list = []
Declaring the variables inside the class declaration makes them "class" members and not instance members. Declaring them inside the __init__ method mak...
How to read the RGB value of a given pixel in Python?
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It's probably best to use the Python Image Library to do this which I'm afraid is a separate download.
The easiest way to do what you want is via the load() method on the Image object which returns a pixel access object which you can ma...
Python matplotlib multiple bars
...rs in matplotlib, when I tried to call the bar function multiple times, they overlap and as seen the below figure the highest value red can be seen only.
How can I plot the multiple bars with dates on the x-axes?
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How to make an immutable object in Python?
...e never needed this, it just struck me that making an immutable object in Python could be slightly tricky. You can't just override __setattr__ , because then you can't even set attributes in the __init__ . Subclassing a tuple is a trick that works:
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