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Converting a generic list to a CSV string
...s.
List<int> myValues;
string csv = String.Join(",", myValues.Select(x => x.ToString()).ToArray());
For the general case:
IEnumerable<T> myList;
string csv = String.Join(",", myList.Select(x => x.ToString()).ToArray());
As you can see, it's effectively no different. Beware that y...
pandas DataFrame: replace nan values with average of columns
...ng set! Imagine it like this: We have 100 data rows and we consider column x. The first 99 entries of x are NA. We want to split off row 100 as a test set. Let's assume row 100 has value 20 in column x. Then you will replace all entries in the training set in column x with 20, a value coming 100% fr...
Python list of dictionaries search
...
You can use a generator expression:
>>> dicts = [
... { "name": "Tom", "age": 10 },
... { "name": "Mark", "age": 5 },
... { "name": "Pam", "age": 7 },
... { "name": "Dick", "age": 12 }
... ]
>>> next(item for item ...
In Python, how do I determine if an object is iterable?
...ter() would be better:
def iterable(obj):
try:
iter(obj)
except Exception:
return False
else:
return True
We've used iter() in our code as well for this purpose, but I've lately started to get more and more annoyed by objects which only have __getitem__ being c...
How can I find a specific element in a List?
...
Use a lambda expression
MyClass result = list.Find(x => x.GetId() == "xy");
Note: C# has a built-in syntax for properties. Instead of writing getter and setter methods (as you might be used to from Java), write
private string _id;...
What does `someObject.new` do in Java?
...e with a containing instance other than this then you have to use the prefix notation.
Foo f = new Foo(5);
Foo.Bar b = f.new Bar();
b.printVal(); // prints 5
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improve this answer
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Merging dictionaries in C#
...tionary(pair => pair.Key, pair => pair.Value);
That will throw an exception if you get any duplicate keys.
EDIT: If you use ToLookup then you'll get a lookup which can have multiple values per key. You could then convert that to a dictionary:
var result = dictionaries.SelectMany(dict =>...
Setting environment variables on OS X
What is the proper way to modify environment variables like PATH in OS X?
31 Answers
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Understanding repr( ) function in Python
...
>>> x = 'foo'
>>> x
'foo'
So the name x is attached to 'foo' string. When you call for example repr(x) the interpreter puts 'foo' instead of x and then calls repr('foo').
>>> repr(x)
"'foo'"
>>> x.__...
Matplotlib different size subplots
...
import numpy as np
import matplotlib.pyplot as plt
# generate some data
x = np.arange(0, 10, 0.2)
y = np.sin(x)
# plot it
f, (a0, a1) = plt.subplots(1, 2, gridspec_kw={'width_ratios': [3, 1]})
a0.plot(x, y)
a1.plot(y, x)
f.tight_layout()
f.savefig('grid_figure.pdf')
...