Ggtcf

I have four excel files that I have loaded onto R using list.files, and have used lapply to read them in.
My code is:

 my_files <- list.files(pattern = '*.xlsx')
 my_list <- lapply(my_files ,read_excel)

The files contain many different columns:

 lapply(my_list ,colnames)
 > lapply(my_list ,colnames)
 [[1]]
 [1] "JobCard Branch" "Customer Name" "Primary Contact No" "Alt No 1" 
 [5] "Alt No 2" "Reg No" 
 [[2]]
 [1] "CUSTOMER" "Primary Contact No" "Alt No 1" "REG NO#" 
 [5] "VehModel" "Last Service Outlet"
 [[3]]
 [1] "Company Name" "JobCard Branch" "Service_Branch" 
 [4] "HUB" "Customer Code" "Address" 
 [7] "Address Line2" "Primary Contact No" "Alt No 1" 
 [10] "Alt No 2" "Alt No 3" "Zip" 
 [13] "Source" "City" "Vehicle Model" 
 [16] "Make" "Reg No" "Chasis No" 
 [[4]]
 [1] "Last Call Date" "Reg.No" "Model" "Customer Name" "Contact Number" "Booked Outlet" 
 > 

Could someone let me know if I can extract only the registration number columns ("Reg No","REG NO#","Reg No","Reg.No") from all these tibbles using rbind or any other function.

We could create a vector of column names (cols) which we want to extract and then use lapply to loop over list of dataframes and subset the columns which match cols.

cols <- c("Reg No","REG NO#","Reg No","Reg.No")
data.frame(unlist(lapply(my_list, function(x) 
 x[names(x) %in% cols]), use.names = FALSE))

A reproducible example

df1 <- data.frame(a = 1:5, b = 2:6)
df2 <- data.frame(a1 = 1:4, new_s = 2:5)
df3 <- data.frame(abc = 1:4)
list_df <- list(df1, df2, df3)


cols <- c("a", "a1", "abc")
data.frame(new = unlist(lapply(list_df, function(x) 
 x[names(x) %in% cols]),use.names = FALSE))

# new
# 1 1
# 2 2
# 3 3
# 4 4
# 5 5
# 6 1
# 7 2
# 8 3
# 9 4
#10 1
#11 2
#12 3
#13 4

You may try using grep in case insensitive mode:

lapply(my_list, function(x) 
 y <- colnames(x)
 y[grep("\breg\b", y, ignore.case=TRUE)]
)

This uses the regex pattern breg]b in case insensitive mode, to find the column names which match what you want.