如何用reduce合并多个data.frames并获得有序输出?

有一个经典的方法 how to simultaneously merge multiple data.frames in a list .

然而,产量有点混乱。

例子

> L
[[1]]
  a b c  d e
1 5 2 4 10 1

[[2]]
  a b c d e
1 6 7 4 6 1

[[3]]
  a b c d
1 7 3 5 5

[[4]]
  a b c d
1 5 2 6 5

[[5]]
  a b c d
1 4 4 2 8

输出的行 Reduce(.) 由5,1,4,2,3排序,这可能意味着从外部到内部的某种缩减工作。

> Reduce(function(...) merge(..., all=TRUE), L)
> Reduce(function(x, y) merge(x, y, all=TRUE, by=intersect(names(x), names(y))), L)  # same
  a b c  d  e
1 4 4 2  8 NA
2 5 2 4 10  1
3 5 2 6  5 NA
4 6 7 4  6  1
5 7 3 5  5 NA

不管怎样,有没有一种方法可以稍微更改代码以获得如下所示的有序输出?

#   a b c  d  e
# 1 5 2 4 10  1
# 2 6 7 4  6  1
# 3 7 3 5  5 NA
# 4 5 2 6  5 NA
# 5 4 4 2  8 NA

数据

L <- list(structure(list(a = 5L, b = 2L, c = 4L, d = 10L, e = 1L), class = "data.frame", row.names = c(NA, 
-1L)), structure(list(a = 6L, b = 7L, c = 4L, d = 6L, e = 1L), class = "data.frame", row.names = c(NA, 
-1L)), structure(list(a = 7L, b = 3L, c = 5L, d = 5L), class = "data.frame", row.names = c(NA, 
-1L)), structure(list(a = 5L, b = 2L, c = 6L, d = 5L), class = "data.frame", row.names = c(NA, 
-1L)), structure(list(a = 4L, b = 4L, c = 2L, d = 8L), class = "data.frame", row.names = c(NA, 
-1L)))