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Naming returned columns in Pandas aggregate function? [duplicate]
...er, this does not work with lambda functions, since they are anonymous and all return <lambda>, which causes a name collision:
>>> df.groupby('A').agg({'B': [lambda x: x.min(), lambda x: x.max]})
SpecificationError: Function names must be unique, found multiple named <lambda>
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Python 2.7: Print to File
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In Python 3.0+, print is a function, which you'd call with print(...). In earlier version, print is a statement, which you'd make with print ....
To print to a file in Python earlier than 3.0, you'd do:
print >> f, 'what ever %d', i
The >> operator directs pr...
How can I test a Windows DLL file to determine if it is 32 bit or 64 bit? [duplicate]
I'd like to write a test script or program that asserts that all DLL files in a given directory are of a particular build type.
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What is the type of lambda when deduced with “auto” in C++11?
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The type of a lambda expression is unspecified.
But they are generally mere syntactic sugar for functors. A lambda is translated directly into a functor. Anything inside the [] are turned into constructor parameters and members of the functor object, and the parameters inside () are turned ...
C# Float expression: strange behavior when casting the result float to int
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First of all, I assume that you know that 6.2f * 10 is not exactly 62 due to floating point rounding (it's actually the value 61.99999809265137 when expressed as a double) and that your question is only about why two seemingly identic...
Java: parse int value from a char
...So e.g. '0' in ascii is 48, '1' is 49, etc. So if you take '2' - '0' you really just get 50 - 48 = 2. Have a look at an ASCII table in order to understand this principle better. Also, 'x' means get the ascii value of the character in Java.
– Kevin Van Ryckegem
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Why does Python use 'magic methods'?
...lable, an object implements a method, def __len__(self) , and then it is called when you write len(obj) .
7 Answers
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Swift Beta performance: sorting arrays
...t))
// [-1, 0, 2, 2, 5, 8, 1234]
// [-1, 0, 2, 2, 5, 8, 1234]
Both are called in the same program as written.
var x_swift = CInt[](count: n, repeatedValue: 0)
var x_c = CInt[](count: n, repeatedValue: 0)
for var i = 0; i < n; ++i {
x_swift[i] = CInt(random())
x_c[i] = CInt(random())
}...
How to get number of entries in a Lua table?
...ual, any of 3, 5 and 9 are valid results for #t. According to the manual, calling # on non-sequences is undefined. That means that any result (-1, 3, 3.14, 5, 9) is valid.
– cubuspl42
May 12 '14 at 20:08
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Getting the SQL from a Django QuerySet [duplicate]
...t the queryset's query attribute.
>>> queryset = MyModel.objects.all()
>>> print(queryset.query)
SELECT "myapp_mymodel"."id", ... FROM "myapp_mymodel"
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