大约有 49,000 项符合查询结果（耗时：0.0376秒） [XML]
Can dplyr package be used for conditional mutating?
...f %>%
mutate(g = ifelse(a == 2 | a == 5 | a == 7 | (a == 1 & b == 4), 2,
ifelse(a == 0 | a == 1 | a == 4 | a == 3 | c == 4, 3, NA)))
Added - if_else: Note that in dplyr 0.5 there is an if_else function defined so an alternative would be to replace ifelse with if_else; howev...
Validating IPv4 addresses with regexp
I've been trying to get an efficient regex for IPv4 validation, but without much luck. It seemed at one point I had had it with (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?(\.|$)){4} , but it produces some strange results:
...
What is the optimal Jewish toenail cutting algorithm?
...ort ifilter, permutations
validseqs = ifilter(isValid, permutations([1,2,3,4,5]))
for i in validseqs:
print i
(1, 3, 5, 2, 4)
(1, 4, 2, 5, 3)
(2, 4, 1, 3, 5)
(2, 4, 1, 5, 3)
(2, 5, 3, 1, 4)
(3, 1, 4, 2, 5)
(3, 1, 5, 2, 4)
(3, 5, 1, 4, 2)
(3, 5, 2, 4, 1)
(4, 1, 3, 5, 2)
(4, 2, 5, 1, 3)
(4, 2, 5,...
What is the ultimate postal code and zip regex?
...le IMO. But you would still be missing on the validation part: Zip code 12345 may exist, but 12346 not, maybe 12344 doesn't exist either. How do you check for that with a regex?
You can't.
share
|
...
Pandas index column title or name
...
394
You can just get/set the index via its name property
In [7]: df.index.name
Out[7]: 'Index Title...
How can I plot with 2 different y-axes?
...ach set of points has its own (different) y-axis (i.e., in positions 2 and 4 on the figure) but the points appear superimposed on the same figure.
...
GIF Animated 扩展：可点击透明背景动画GIF播放器 · App Inventor 2 中文网
...件。图像可以是可点击的并支持透明背景。
包名：com.KIO4_AniGif.aix / com.KIO4_AniGif10.aix（Android 10+）
技术基础：基于 GifDecoder.java 开发，包含大量修改
最后更新：2022年6月21日
下载链接
扩展文件需从外部网站获...
Determine the data types of a data frame's columns
...st few values of each variable):
str(my.data)
'data.frame': 5 obs. of 4 variables:
$ y : num 1.03 1.599 -0.818 0.872 -2.682
$ x1: int 1 2 3 4 5
$ x2: logi TRUE TRUE FALSE FALSE FALSE
$ X3: Factor w/ 5 levels "a","b","c","d",..: 1 2 3 4 5
@Gavin Simpson's approach is also streamlined, but p...
How to compare two strings in dot separated version format in Bash?
Is there any way to compare such strings on bash, e.g.: 2.4.5 and 2.8 and 2.4.5.1 ?
29 Answers
...