大约有 43,200 项符合查询结果（耗时：0.0217秒） [XML]
How exactly does tail recursion work?
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169
The compiler is simply able to transform this
int fac_times (int n, int acc) {
if (n == 0...
How can I check if a string represents an int, without using try/except?
... any way to tell whether a string represents an integer (e.g., '3' , '-17' but not '3.14' or 'asfasfas' ) Without using a try/except mechanism?
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Determine the data types of a data frame's columns
...se ?str(). To explore some examples, let's make some data:
set.seed(3221) # this makes the example exactly reproducible
my.data <- data.frame(y=rnorm(5),
x1=c(1:5),
x2=c(TRUE, TRUE, FALSE, FALSE, FALSE),
X3=letters[1:5])
@...
Expand a random range from 1–5 to 1–7
Given a function which produces a random integer in the range 1 to 5, write a function which produces a random integer in the range 1 to 7.
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Format number to always show 2 decimal places
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1197
(Math.round(num * 100) / 100).toFixed(2);
Live Demo
var num1 = "1";
document.getEleme...
How to split a column into two columns?
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11 Answers
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Generate a random number in the range 1 - 10
...here a way to tell pg's random() function to get me only numbers between 1 and 10?
7 Answers
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Numpy: Divide each row by a vector element
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187
Here you go. You just need to use None (or alternatively np.newaxis) combined with broadcastin...
Does the ternary operator exist in R?
... returns the latest evaluation, if-else is equivalent to ?:.
> a <- 1
> x <- if(a==1) 1 else 2
> x
[1] 1
> x <- if(a==2) 1 else 2
> x
[1] 2
The power of R is vectorization. The vectorization of the ternary operator is ifelse:
> a <- c(1, 2, 1)
> x <- ifelse(a=...
Apply pandas function to column to create multiple new columns?
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13 Answers
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