大约有 1,900 项符合查询结果（耗时：0.0172秒） [XML]
Pandas - Get first row value of a given column
...row, use iloc:
In [31]: df_test.iloc[0]
Out[31]:
ATime 1.2
X 2.0
Y 15.0
Z 2.0
Btime 1.2
C 12.0
D 25.0
E 12.0
Name: 0, dtype: float64
To select the ith value in the Btime column you could use:
In [30]: df_test['Btime'].iloc[0]
Out[30]: 1.2
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How to write a switch statement in Ruby
...
In Ruby 2.0, you can also use lambdas in case statements, as follows:
is_even = ->(x) { x % 2 == 0 }
case number
when 0 then puts 'zero'
when is_even then puts 'even'
else puts 'odd'
end
You can also create your own comparator...
Will code in a Finally statement fire if I return a value in a Try block?
...non-CLS compliant exceptions.
Asynchronous ThreadAbortException
As of .NET 2.0, a ThreadAbortException will no longer prevent a finally from running. ThreadAbortException is now hoisted to before or after the finally. The finally will always run and will not be interrupted by a thread abort, so long...
Abstract classes in Swift Language
...going to be to use a Protocol, which is like a Java Interface.
With Swift 2.0, you can then add method implementations and calculated property implementations using protocol extensions. Your only restrictions are that you can't provide member variables or constants and there is no dynamic dispatch....
Is there a way of setting culture for a whole application? All current threads and new threads?
...ere is a private static field on CultureInfo (m_userDefaultCulture in .NET 2.0 mscorlib, s_userDefaultCulture in .NET 4.0 mscorlib) that controls what CurrentCulture returns if a thread has not set that property on itself.
This does not change the native thread locale and it is probably not a good ...
Average of 3 long integers
...max 2 values
long mean;
if (min > 0) {
mean = min + ((tmp - min) * (2.0 / 3)); //Average of all 3 values
} else if (median > 0) {
mean = min;
while (mean != tmp) {
mean += 2;
tmp--;
}
} else if (max > 0) {
mean = max;
while (mean != tmp) {
mea...
What is NSLayoutConstraint “UIView-Encapsulated-Layout-Height” and how should I go about forcing it
...hing and I get what I expect on screen):
myTableView.estimatedRowHeight = 2.0; // any number but 2.0 is the smallest one that works
with or without this line:
myTableView.rowHeight = UITableViewAutomaticDimension; // by itself this line only doesn't help fix my specific problem
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When is finally run if you throw an exception from the catch block?
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Interesting... On .NET Core 2.0, the finally part runs after the unhandled exception.
– Mahdi Ghiasi
Jul 22 '18 at 7:09
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How do I parallelize a simple Python loop?
...nd here's the output:
$ python3 -m futuretest
original inputs: [0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0]
total time to execute 33 = sum([0, 3, 3, 4, 3, 5, 1, 5, 5, 4])
time saved by parallellizing: 27.68999981880188
returned in order given: [0, 4, 16, 36, 64, 100, 144, 196, 256, 324]
Mul...
What does a double * (splat) operator do
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Ruby 2.0 introduced keyword arguments, and ** acts like *, but for keyword arguments. It returns a Hash with key / value pairs.
For this code:
def foo(a, *b, **c)
[a, b, c]
end
Here's a demo:
> foo 10
=> [10, [], {}]
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