I'd like to take data of the form
我想要索取表格的资料。
before = data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2'))
attr type
1 1 foo_and_bar
2 30 foo_and_bar_2
3 4 foo_and_bar
4 6 foo_and_bar_2
and use split()
on the column "type
" from above to get something like this:
在上面的列“类型”中使用split()来获得如下内容:
attr type_1 type_2
1 1 foo bar
2 30 foo bar_2
3 4 foo bar
4 6 foo bar_2
I came up with something unbelievably complex involving some form of apply
that worked, but I've since misplaced that. It seemed far too complicated to be the best way. I can use strsplit
as below, but then unclear how to get that back into 2 columns in the data frame.
我想出了一些难以置信的复杂的东西,涉及到一些有用的应用,但我把它放错了地方。这似乎太复杂了,不可能是最好的方法。我可以使用strsplit,但不清楚如何将它返回到数据框架中的2列。
> strsplit(as.character(before$type),'_and_')
[[1]]
[1] "foo" "bar"
[[2]]
[1] "foo" "bar_2"
[[3]]
[1] "foo" "bar"
[[4]]
[1] "foo" "bar_2"
Thanks for any pointers. I've not quite groked R lists just yet.
感谢任何指针。我还没有弄清楚R的列表。
15 个解决方案
#1
185
Use stringr::str_split_fixed
使用stringr::str_split_fixed
library(stringr)
str_split_fixed(before$type, "_and_", 2)
#2
106
Another option is to use the new tidyr package.
另一种选择是使用新的tidyr包。
library(dplyr)
library(tidyr)
before <- data.frame(
attr = c(1, 30 ,4 ,6 ),
type = c('foo_and_bar', 'foo_and_bar_2')
)
before %>%
separate(type, c("foo", "bar"), "_and_")
## attr foo bar
## 1 1 foo bar
## 2 30 foo bar_2
## 3 4 foo bar
## 4 6 foo bar_2
#3
38
Yet another approach: use rbind
on out
:
另一种方法:使用rbind:
before <- data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2'))
out <- strsplit(as.character(before$type),'_and_')
do.call(rbind, out)
[,1] [,2]
[1,] "foo" "bar"
[2,] "foo" "bar_2"
[3,] "foo" "bar"
[4,] "foo" "bar_2"
And to combine:
并结合:
data.frame(before$attr, do.call(rbind, out))
#4
37
5 years later adding the obligatory data.table
solution
5年后增加了强制性数据。表解决方案
library(data.table) ## v 1.9.6+
setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_")]
before
# attr type type1 type2
# 1: 1 foo_and_bar foo bar
# 2: 30 foo_and_bar_2 foo bar_2
# 3: 4 foo_and_bar foo bar
# 4: 6 foo_and_bar_2 foo bar_2
We could also both make sure that the resulting columns will have correct types and improve performance by adding type.convert
and fixed
arguments (since "_and_"
isn't really a regex)
我们还可以确保生成的列具有正确的类型,并通过添加类型来提高性能。转换和固定参数(因为“_and_”并不是真正的正则表达式)
setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_", type.convert = TRUE, fixed = TRUE)]
#5
29
Notice that sapply with "[" can be used to extract either the first or second items in those lists so:
请注意,sapply和“[”可以用来提取这些列表中的第一项或第二项:
before$type_1 <- sapply(strsplit(as.character(before$type),'_and_'), "[", 1)
before$type_2 <- sapply(strsplit(as.character(before$type),'_and_'), "[", 2)
before$type <- NULL
And here's a gsub method:
这是一个gsub方法:
before$type_1 <- gsub("_and_.+$", "", before$type)
before$type_2 <- gsub("^.+_and_", "", before$type)
before$type <- NULL
#6
25
here is a one liner along the same lines as aniko's solution, but using hadley's stringr package:
这是一个与aniko的解决方案相同的一行,但是使用hadley的stringr包:
do.call(rbind, str_split(before$type, '_and_'))
#7
16
To add to the options, you could also use my splitstackshape::cSplit
function like this:
要添加到选项中,您还可以使用我的splitstackshape::cSplit函数:
library(splitstackshape)
cSplit(before, "type", "_and_")
# attr type_1 type_2
# 1: 1 foo bar
# 2: 30 foo bar_2
# 3: 4 foo bar
# 4: 6 foo bar_2
#8
11
An easy way is to use sapply()
and the [
function:
一种简单的方法是使用sapply()和[函数:
before <- data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2'))
out <- strsplit(as.character(before$type),'_and_')
For example:
例如:
> data.frame(t(sapply(out, `[`)))
X1 X2
1 foo bar
2 foo bar_2
3 foo bar
4 foo bar_2
sapply()
's result is a matrix and needs transposing and casting back to a data frame. It is then some simple manipulations that yield the result you wanted:
sapply()的结果是一个矩阵,需要将其转换回数据帧。然后是一些简单的操作,产生你想要的结果:
after <- with(before, data.frame(attr = attr))
after <- cbind(after, data.frame(t(sapply(out, `[`))))
names(after)[2:3] <- paste("type", 1:2, sep = "_")
At this point, after
is what you wanted
在这一点上,是你想要的。
> after
attr type_1 type_2
1 1 foo bar
2 30 foo bar_2
3 4 foo bar
4 6 foo bar_2
#9
6
Here is a base R one liner that overlaps a number of previous solutions, but returns a data.frame with the proper names.
这里是一个基本的R,它与前面的一些解决方案重叠,但是返回一个具有专有名称的数据。
out <- setNames(data.frame(before$attr,
do.call(rbind, strsplit(as.character(before$type),
split="_and_"))),
c("attr", paste0("type_", 1:2)))
out
attr type_1 type_2
1 1 foo bar
2 30 foo bar_2
3 4 foo bar
4 6 foo bar_2
It uses strsplit
to break up the variable, and data.frame
with do.call
/rbind
to put the data back into a data.frame. The additional incremental improvement is the use of setNames
to add variable names to the data.frame.
它使用strsplit来分解变量和数据。调用/rbind将数据返回到数据。frame。额外的增量改进是使用setNames为数据集添加变量名。
#10
4
Another approach if you want to stick with strsplit()
is to use the unlist()
command. Here's a solution along those lines.
如果要使用strsplit(),另一种方法是使用unlist()命令。这里有一个沿着这些线的解。
tmp <- matrix(unlist(strsplit(as.character(before$type), '_and_')), ncol=2,
byrow=TRUE)
after <- cbind(before$attr, as.data.frame(tmp))
names(after) <- c("attr", "type_1", "type_2")
#11
3
Since R version 3.4.0 you can use strcapture()
from the utils package (included with base R installs), binding the output onto the other column(s).
从R版本3.4.0开始,您可以使用utils包中的strcapture(),将输出绑定到其他列上。
out <- strcapture(
"(.*)_and_(.*)",
as.character(before$type),
data.frame(type_1 = character(), type_2 = character())
)
cbind(before["attr"], out)
# attr type_1 type_2
# 1 1 foo bar
# 2 30 foo bar_2
# 3 4 foo bar
# 4 6 foo bar_2
#12
3
This question is pretty old but I'll add the solution I found the be the simplest at present.
这个问题已经很老了,但是我要添加一个解决方案,我发现它是目前最简单的。
library(reshape2)
before = data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2'))
newColNames <- c("type1", "type2")
newCols <- colsplit(before$type, "_and_", newColNames)
after <- cbind(before, newCols)
after$type <- NULL
after
#13
2
The subject is almost exhausted, I 'd like though to offer a solution to a slightly more general version where you don't know the number of output columns, a priori. So for example you have
这个主题几乎是用尽了,我想要提供一个稍微一般化的版本的解决方案,你不知道输出列的数量,一个先验的。举个例子。
before = data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2', 'foo_and_bar_2_and_bar_3', 'foo_and_bar'))
attr type
1 1 foo_and_bar
2 30 foo_and_bar_2
3 4 foo_and_bar_2_and_bar_3
4 6 foo_and_bar
We can't use dplyr separate()
because we don't know the number of the result columns before the split, so I have then created a function that uses stringr
to split a column, given the pattern and a name prefix for the generated columns. I hope the coding patterns used, are correct.
我们不能使用dplyr单独(),因为我们不知道拆分前的结果列的数量,所以我创建了一个函数,它使用stringr来拆分列,给出了生成列的模式和名称前缀。我希望使用的编码模式是正确的。
split_into_multiple <- function(column, pattern = ", ", into_prefix){
cols <- str_split_fixed(column, pattern, n = Inf)
# Sub out the ""'s returned by filling the matrix to the right, with NAs which are useful
cols[which(cols == "")] <- NA
cols <- as.tibble(cols)
# name the 'cols' tibble as 'into_prefix_1', 'into_prefix_2', ..., 'into_prefix_m'
# where m = # columns of 'cols'
m <- dim(cols)[2]
names(cols) <- paste(into_prefix, 1:m, sep = "_")
return(cols)
}
We can then use split_into_multiple
in a dplyr pipe as follows:
然后我们可以在dplyr管道中使用split_into_multiple:
after <- before %>%
bind_cols(split_into_multiple(.$type, "_and_", "type")) %>%
# selecting those that start with 'type_' will remove the original 'type' column
select(attr, starts_with("type_"))
>after
attr type_1 type_2 type_3
1 1 foo bar <NA>
2 30 foo bar_2 <NA>
3 4 foo bar_2 bar_3
4 6 foo bar <NA>
And then we can use gather
to tidy up...
然后我们可以用集合来整理…
after %>%
gather(key, val, -attr, na.rm = T)
attr key val
1 1 type_1 foo
2 30 type_1 foo
3 4 type_1 foo
4 6 type_1 foo
5 1 type_2 bar
6 30 type_2 bar_2
7 4 type_2 bar_2
8 6 type_2 bar
11 4 type_3 bar_3
#14
2
base but probably slow:
基础但可能缓慢:
n <- 1
for(i in strsplit(as.character(before$type),'_and_')){
before[n, 'type_1'] <- i[[1]]
before[n, 'type_2'] <- i[[2]]
n <- n + 1
}
## attr type type_1 type_2
## 1 1 foo_and_bar foo bar
## 2 30 foo_and_bar_2 foo bar_2
## 3 4 foo_and_bar foo bar
## 4 6 foo_and_bar_2 foo bar_2
#15
-4
tp <- c("a-c","d-e-f","g-h-i","m-n")
temp = strsplit(as.character(tp),'-')
x=c();
y=c();
z=c();
#tab=data.frame()
#tab= cbind(tab,c(x,y,z))
for(i in 1:length(temp) )
{
l = length(temp[[i]]);
if(l==2)
{
x=c(x,temp[[i]][1]);
y=c(y,"NA")
z=c(z,temp[[i]][2]);
df= as.data.frame(cbind(x,y,z))
}else
{
x=c(x,temp[[i]][1]);
y=c(y,temp[[i]][2]);
z=c(z,temp[[i]][3]);
df= as.data.frame(cbind(x,y,z))
}
}
#1
185
Use stringr::str_split_fixed
使用stringr::str_split_fixed
library(stringr)
str_split_fixed(before$type, "_and_", 2)
#2
106
Another option is to use the new tidyr package.
另一种选择是使用新的tidyr包。
library(dplyr)
library(tidyr)
before <- data.frame(
attr = c(1, 30 ,4 ,6 ),
type = c('foo_and_bar', 'foo_and_bar_2')
)
before %>%
separate(type, c("foo", "bar"), "_and_")
## attr foo bar
## 1 1 foo bar
## 2 30 foo bar_2
## 3 4 foo bar
## 4 6 foo bar_2
#3
38
Yet another approach: use rbind
on out
:
另一种方法:使用rbind:
before <- data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2'))
out <- strsplit(as.character(before$type),'_and_')
do.call(rbind, out)
[,1] [,2]
[1,] "foo" "bar"
[2,] "foo" "bar_2"
[3,] "foo" "bar"
[4,] "foo" "bar_2"
And to combine:
并结合:
data.frame(before$attr, do.call(rbind, out))
#4
37
5 years later adding the obligatory data.table
solution
5年后增加了强制性数据。表解决方案
library(data.table) ## v 1.9.6+
setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_")]
before
# attr type type1 type2
# 1: 1 foo_and_bar foo bar
# 2: 30 foo_and_bar_2 foo bar_2
# 3: 4 foo_and_bar foo bar
# 4: 6 foo_and_bar_2 foo bar_2
We could also both make sure that the resulting columns will have correct types and improve performance by adding type.convert
and fixed
arguments (since "_and_"
isn't really a regex)
我们还可以确保生成的列具有正确的类型,并通过添加类型来提高性能。转换和固定参数(因为“_and_”并不是真正的正则表达式)
setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_", type.convert = TRUE, fixed = TRUE)]
#5
29
Notice that sapply with "[" can be used to extract either the first or second items in those lists so:
请注意,sapply和“[”可以用来提取这些列表中的第一项或第二项:
before$type_1 <- sapply(strsplit(as.character(before$type),'_and_'), "[", 1)
before$type_2 <- sapply(strsplit(as.character(before$type),'_and_'), "[", 2)
before$type <- NULL
And here's a gsub method:
这是一个gsub方法:
before$type_1 <- gsub("_and_.+$", "", before$type)
before$type_2 <- gsub("^.+_and_", "", before$type)
before$type <- NULL
#6
25
here is a one liner along the same lines as aniko's solution, but using hadley's stringr package:
这是一个与aniko的解决方案相同的一行,但是使用hadley的stringr包:
do.call(rbind, str_split(before$type, '_and_'))
#7
16
To add to the options, you could also use my splitstackshape::cSplit
function like this:
要添加到选项中,您还可以使用我的splitstackshape::cSplit函数:
library(splitstackshape)
cSplit(before, "type", "_and_")
# attr type_1 type_2
# 1: 1 foo bar
# 2: 30 foo bar_2
# 3: 4 foo bar
# 4: 6 foo bar_2
#8
11
An easy way is to use sapply()
and the [
function:
一种简单的方法是使用sapply()和[函数:
before <- data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2'))
out <- strsplit(as.character(before$type),'_and_')
For example:
例如:
> data.frame(t(sapply(out, `[`)))
X1 X2
1 foo bar
2 foo bar_2
3 foo bar
4 foo bar_2
sapply()
's result is a matrix and needs transposing and casting back to a data frame. It is then some simple manipulations that yield the result you wanted:
sapply()的结果是一个矩阵,需要将其转换回数据帧。然后是一些简单的操作,产生你想要的结果:
after <- with(before, data.frame(attr = attr))
after <- cbind(after, data.frame(t(sapply(out, `[`))))
names(after)[2:3] <- paste("type", 1:2, sep = "_")
At this point, after
is what you wanted
在这一点上,是你想要的。
> after
attr type_1 type_2
1 1 foo bar
2 30 foo bar_2
3 4 foo bar
4 6 foo bar_2
#9
6
Here is a base R one liner that overlaps a number of previous solutions, but returns a data.frame with the proper names.
这里是一个基本的R,它与前面的一些解决方案重叠,但是返回一个具有专有名称的数据。
out <- setNames(data.frame(before$attr,
do.call(rbind, strsplit(as.character(before$type),
split="_and_"))),
c("attr", paste0("type_", 1:2)))
out
attr type_1 type_2
1 1 foo bar
2 30 foo bar_2
3 4 foo bar
4 6 foo bar_2
It uses strsplit
to break up the variable, and data.frame
with do.call
/rbind
to put the data back into a data.frame. The additional incremental improvement is the use of setNames
to add variable names to the data.frame.
它使用strsplit来分解变量和数据。调用/rbind将数据返回到数据。frame。额外的增量改进是使用setNames为数据集添加变量名。
#10
4
Another approach if you want to stick with strsplit()
is to use the unlist()
command. Here's a solution along those lines.
如果要使用strsplit(),另一种方法是使用unlist()命令。这里有一个沿着这些线的解。
tmp <- matrix(unlist(strsplit(as.character(before$type), '_and_')), ncol=2,
byrow=TRUE)
after <- cbind(before$attr, as.data.frame(tmp))
names(after) <- c("attr", "type_1", "type_2")
#11
3
Since R version 3.4.0 you can use strcapture()
from the utils package (included with base R installs), binding the output onto the other column(s).
从R版本3.4.0开始,您可以使用utils包中的strcapture(),将输出绑定到其他列上。
out <- strcapture(
"(.*)_and_(.*)",
as.character(before$type),
data.frame(type_1 = character(), type_2 = character())
)
cbind(before["attr"], out)
# attr type_1 type_2
# 1 1 foo bar
# 2 30 foo bar_2
# 3 4 foo bar
# 4 6 foo bar_2
#12
3
This question is pretty old but I'll add the solution I found the be the simplest at present.
这个问题已经很老了,但是我要添加一个解决方案,我发现它是目前最简单的。
library(reshape2)
before = data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2'))
newColNames <- c("type1", "type2")
newCols <- colsplit(before$type, "_and_", newColNames)
after <- cbind(before, newCols)
after$type <- NULL
after
#13
2
The subject is almost exhausted, I 'd like though to offer a solution to a slightly more general version where you don't know the number of output columns, a priori. So for example you have
这个主题几乎是用尽了,我想要提供一个稍微一般化的版本的解决方案,你不知道输出列的数量,一个先验的。举个例子。
before = data.frame(attr = c(1,30,4,6), type=c('foo_and_bar','foo_and_bar_2', 'foo_and_bar_2_and_bar_3', 'foo_and_bar'))
attr type
1 1 foo_and_bar
2 30 foo_and_bar_2
3 4 foo_and_bar_2_and_bar_3
4 6 foo_and_bar
We can't use dplyr separate()
because we don't know the number of the result columns before the split, so I have then created a function that uses stringr
to split a column, given the pattern and a name prefix for the generated columns. I hope the coding patterns used, are correct.
我们不能使用dplyr单独(),因为我们不知道拆分前的结果列的数量,所以我创建了一个函数,它使用stringr来拆分列,给出了生成列的模式和名称前缀。我希望使用的编码模式是正确的。
split_into_multiple <- function(column, pattern = ", ", into_prefix){
cols <- str_split_fixed(column, pattern, n = Inf)
# Sub out the ""'s returned by filling the matrix to the right, with NAs which are useful
cols[which(cols == "")] <- NA
cols <- as.tibble(cols)
# name the 'cols' tibble as 'into_prefix_1', 'into_prefix_2', ..., 'into_prefix_m'
# where m = # columns of 'cols'
m <- dim(cols)[2]
names(cols) <- paste(into_prefix, 1:m, sep = "_")
return(cols)
}
We can then use split_into_multiple
in a dplyr pipe as follows:
然后我们可以在dplyr管道中使用split_into_multiple:
after <- before %>%
bind_cols(split_into_multiple(.$type, "_and_", "type")) %>%
# selecting those that start with 'type_' will remove the original 'type' column
select(attr, starts_with("type_"))
>after
attr type_1 type_2 type_3
1 1 foo bar <NA>
2 30 foo bar_2 <NA>
3 4 foo bar_2 bar_3
4 6 foo bar <NA>
And then we can use gather
to tidy up...
然后我们可以用集合来整理…
after %>%
gather(key, val, -attr, na.rm = T)
attr key val
1 1 type_1 foo
2 30 type_1 foo
3 4 type_1 foo
4 6 type_1 foo
5 1 type_2 bar
6 30 type_2 bar_2
7 4 type_2 bar_2
8 6 type_2 bar
11 4 type_3 bar_3
#14
2
base but probably slow:
基础但可能缓慢:
n <- 1
for(i in strsplit(as.character(before$type),'_and_')){
before[n, 'type_1'] <- i[[1]]
before[n, 'type_2'] <- i[[2]]
n <- n + 1
}
## attr type type_1 type_2
## 1 1 foo_and_bar foo bar
## 2 30 foo_and_bar_2 foo bar_2
## 3 4 foo_and_bar foo bar
## 4 6 foo_and_bar_2 foo bar_2
#15
-4
tp <- c("a-c","d-e-f","g-h-i","m-n")
temp = strsplit(as.character(tp),'-')
x=c();
y=c();
z=c();
#tab=data.frame()
#tab= cbind(tab,c(x,y,z))
for(i in 1:length(temp) )
{
l = length(temp[[i]]);
if(l==2)
{
x=c(x,temp[[i]][1]);
y=c(y,"NA")
z=c(z,temp[[i]][2]);
df= as.data.frame(cbind(x,y,z))
}else
{
x=c(x,temp[[i]][1]);
y=c(y,temp[[i]][2]);
z=c(z,temp[[i]][3]);
df= as.data.frame(cbind(x,y,z))
}
}