大约有 30,000 项符合查询结果（耗时：0.0309秒） [XML]
“for loop” with two variables? [duplicate]
...ested for loop, use:
import itertools
for i, j in itertools.product(range(m>x m>), range(y)):
# Stuff...
If you just want to loop simultaneously, use:
for i, j in zip(range(m>x m>), range(y)):
# Stuff...
Note that if m>x m> and y are not the same length, zip will truncate to the shortest list. As @a...
What is the meaning of the term arena in relation to memory?
...word and how it relates to memory, and found nothing. Here are a few contem>x m>ts in which the author uses the term:
4 Answers...
variable === undefined vs. typeof variable === “undefined”
...for comparison can throw an error whereas a typeof check never will.
For em>x m>ample, the following is used in IE for parsing m>X m>ML:
var m>x m> = new Activem>X m>Object("Microsoft.m>X m>MLDOM");
To check whether it has a loadm>X m>ML method safely:
typeof m>x m>.loadm>X m>ML === "undefined"; // Returns false
On the other hand:
...
Static variable inside of a function in C
...ope.
The scope of variable is where the variable name can be seen. Here, m>x m> is visible only inside function foo().
The lifetime of a variable is the period over which it em>x m>ists. If m>x m> were defined without the keyword static, the lifetime would be from the entry into foo() to the return from foo();...
Test for equality among all elements of a single vector
...
I use this method, which compares the min and the mam>x m>, after dividing by the mean:
# Determine if range of vector is FP 0.
zero_range <- function(m>x m>, tol = .Machine$double.eps ^ 0.5) {
if (length(m>x m>) == 1) return(TRUE)
m>x m> <- range(m>x m>) / mean(m>x m>)
isTRUE(all.equal(m>x m>[1], ...
Does a favicon have to be 32m>x m>32 or 16m>x m>16?
...
Update for 2020: Sticking to the original question of 16m>x m>16 versus 32m>x m>32 icons: the current recommendation should be to provide a 32m>x m>32 icon, skipping 16m>x m>16 entirely. All current browsers and devices support 32m>x m>32 icons. The icon will routinely be upscaled to as much as 192m>x m>192 de...
How to add a border just on the top side of a UIView
...
1
2
Nem>x m>t
202
...
Bad value m>X m>-UA-Compatible for attribute http-equiv on element meta
...
Either m>X m>-UA-Compatible is not "standard" HTML (FSVO "standard" that involves appearing on a publicly editable wiki page referenced by the specification) or the Validator isn't up to date with the current status of that wiki.
At the...
When is “i += m>x m>” different from “i = i + m>x m>” in Python?
... depends entirely on the object i.
+= calls the __iadd__ method (if it em>x m>ists -- falling back on __add__ if it doesn't em>x m>ist) whereas + calls the __add__ method1 or the __radd__ method in a few cases2.
From an API perspective, __iadd__ is supposed to be used for modifying mutable objects in pl...
Fast check for NaN in NumPy
...astest way to check for the occurrence of NaN ( np.nan ) in a NumPy array m>X m> . np.isnan(m>X m>) is out of the question, since it builds a boolean array of shape m>X m>.shape , which is potentially gigantic.
...