Changing Column Names in a List of Data Frames in R
With lapply you can do it as follows.
Create sample data:
df1 <- data.frame(A = 1, B = 2, C = 3)
df2 <- data.frame(X = 1, Y = 2, Z = 3)
dfList <- list(df1,df2)
colnames <- c("USAF","WBAN","YR--MODAHRMN")
Then, lapply over the list using setNames
and supply the vector of new column names as second argument to setNames
:
lapply(dfList, setNames, colnames)
#[[1]]
# USAF WBAN YR--MODAHRMN
#1 1 2 3
#
#[[2]]
# USAF WBAN YR--MODAHRMN
#1 1 2 3
Edit
If you want to assign the data.frames back to the global environment, you can modify the code like this:
dfList <- list(df1 = df1, df2 = df2)
list2env(lapply(dfList, setNames, colnames), .GlobalEnv)
Just change your for-loop into an index for-loop like this:
Data
df1 <- data.frame(a=runif(5), b=runif(5), c=runif(5))
df2 <- data.frame(a=runif(5), b=runif(5), c=runif(5))
dflist <- list(df1,df2)
colnames = c("USAF","WBAN","YR--MODAHRMN")
Solution
for (i in seq_along(dflist)){
colnames(dflist[[i]]) <- colnames
}
Output
> dflist
[[1]]
USAF WBAN YR--MODAHRMN
1 0.8794153 0.7025747 0.2136040
2 0.8805788 0.8253530 0.5467952
3 0.1719539 0.5303908 0.5965716
4 0.9682567 0.5137464 0.4038919
5 0.3172674 0.1403439 0.1539121
[[2]]
USAF WBAN YR--MODAHRMN
1 0.20558383 0.62651334 0.4365940
2 0.43330717 0.85807280 0.2509677
3 0.32614750 0.70782919 0.6319263
4 0.02957656 0.46523151 0.2087086
5 0.58757198 0.09633181 0.6941896
By using for (df in dfList)
you are essentially creating a new df each time and change the column names to that leaving the original list (dfList
) untouched.