英文:
Saving a list of dataframes into separate CSVs in R
问题
我有一个数据框列表：
group_eg <- data.frame(
CID = c(091, 091, 091, 091,
101, 101, 101,
102, 102, 102,
103, 103,
104, 104, 104),
PID_A = c(1091, 1091, 1091, 1091,
1101, 1101, 1101,
1102, 1102, 1102,
1103, 1103,
1104, 1104, 1104),
PID_B = c(2091, 2091, 2091, 2091,
2101, 2101, 2101,
2102, 2102, 2102,
2103, 2103,
2104, 2104, 2104),
text = c("eg1", "eg2", "eg3", "eg3",
"eg4","eg5", "eg6",
"eg7", "eg8","eg9",
"eg10", "eg11",
"eg12", "eg13", "eg14")
)
group_eg_split <- split(group_eg, paste0("output_", ceiling(rleid(group_eg$CID)/2)))
我尝试将列表中的每个数据框保存到单独的CSV文件中，并使用相应的名称。到目前为止，我有以下内容：
lapply(1:length(group_eg_split), function(i) write.csv(group_eg_split[[i]],
file = paste0(names(group_eg_split[i]), ".csv"),
row.names = FALSE))
但它返回一个NULL值。我应该如何修改它？
谢谢！
英文:
I have a list of dataframes:
group_eg <- data.frame(
CID = c(091, 091, 091, 091,
101, 101, 101,
102, 102, 102,
103, 103,
104, 104, 104),
PID_A = c(1091, 1091, 1091, 1091,
1101, 1101, 1101,
1102, 1102, 1102,
1103, 1103,
1104, 1104, 1104),
PID_B = c(2091, 2091, 2091, 2091,
2101, 2101, 2101,
2102, 2102, 2102,
2103, 2103,
2104, 2104, 2104),
text = c("eg1", "eg2", "eg3", "eg3",
"eg4","eg5", "eg6",
"eg7", "eg8","eg9",
"eg10", "eg11",
"eg12", "eg13", "eg14")
)
group_eg_split <- split(group_eg, paste0("output_", ceiling(rleid(group_eg$CID)/2)))
I am trying to save each dataframe in the list to a separate CSV file with its corresponding name. This is what I have so far:
lapply(1:length(group_eg_split), function(i) write.csv(group_eg_split[[i]],
file = paste0(names(group_eg_split[i]), ".csv"),
row.names = FALSE))
But it's returning a NULL value. How can I modify it?
Thank you!
答案1
得分: 0
Your code is correct, but the dataframes are exported in CSV, and it returns NULL because your function write.csv() returns NULL. If you don't want it, you can update your code and return what you want (the exported dataframes or just a message).
lapply(1:length(group_eg_split),
function(i){
write.csv(
group_eg_split[[i]],
file = paste0(names(group_eg_split[i]), ".csv"),
row.names = FALSE)
return(group_eg_split[[i]])
}
)
如果你更喜欢返回消息而不是数据框，可以将 return(...) 替换为 return(print("导出成功。"))。
英文:
Your code is correct <i>ie</i> the dataframes are exported in csv. And it returns NULL because your function write.csv() returns NULL. If you don't wan't it, you can update your code and return what you want (the exported dataframes or just a message).
lapply(1:length(group_eg_split),
function(i){
write.csv(
group_eg_split[[i]],
file = paste0(names(group_eg_split[i]), ".csv"),
row.names = FALSE)
return(group_eg_split[[i]])
}
)
You can replace return(...) by return(print("Export OK.")) if you prefer a message rather than the dataframes.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论