Use import()
to import a list of data frames from a vector of file names or from a multi-object file (Excel workbook, .Rdata file, zipped directory in a zip file, or HTML file)
Usage
import_list(
file,
setclass = getOption("rio.import.class", "data.frame"),
which,
rbind = FALSE,
rbind_label = "_file",
rbind_fill = TRUE,
...
)
Arguments
- file
A character string containing a single file name for a multi-object file (e.g., Excel workbook, zip file, or HTML file), or a vector of file paths for multiple files to be imported.
- setclass
An optional character vector specifying one or more classes to set on the import. By default, the return object is always a “data.frame”. Allowed values include “tbl_df”, “tbl”, or “tibble” (if using tibble), “arrow”, “arrow_table” (if using arrow table; the suggested package
arrow
must be installed) or “data.table” (if using data.table). Other values are ignored, such that a data.frame is returned. The parameter takes precedents over parameters in ... which set a different class.- which
If
file
is a single file path, this specifies which objects should be extracted (passed toimport()
'swhich
argument). Ignored otherwise.- rbind
A logical indicating whether to pass the import list of data frames through
data.table::rbindlist()
.- rbind_label
If
rbind = TRUE
, a character string specifying the name of a column to add to the data frame indicating its source file.- rbind_fill
If
rbind = TRUE
, a logical indicating whether to set thefill = TRUE
(and fill missing columns withNA
).- ...
Additional arguments passed to
import()
. Behavior may be unexpected if files are of different formats.
Value
If rbind=FALSE
(the default), a list of a data frames. Otherwise, that list is passed to data.table::rbindlist()
with fill = TRUE
and returns a data frame object of class set by the setclass
argument; if this operation fails, the list is returned.
Details
When file is a vector of file paths and any files are missing, those files are ignored (with warnings) and this function will not raise any error.
Examples
## For demo, a temp. file path is created with the file extension .xlsx
xlsx_file <- tempfile(fileext = ".xlsx")
export(
list(
mtcars1 = mtcars[1:10, ],
mtcars2 = mtcars[11:20, ],
mtcars3 = mtcars[21:32, ]
),
xlsx_file
)
# import a single file from multi-object workbook
import(xlsx_file, sheet = "mtcars1")
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> 1 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
#> 2 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
#> 3 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
#> 4 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
#> 5 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
#> 6 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
#> 7 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
#> 8 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
#> 9 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
#> 10 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4
# import all worksheets, the return value is a list
import_list(xlsx_file)
#> $mtcars1
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> 1 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
#> 2 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
#> 3 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
#> 4 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
#> 5 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
#> 6 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
#> 7 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
#> 8 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
#> 9 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
#> 10 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4
#>
#> $mtcars2
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> 1 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4
#> 2 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3
#> 3 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3
#> 4 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3
#> 5 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4
#> 6 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4
#> 7 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4
#> 8 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
#> 9 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
#> 10 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1
#>
#> $mtcars3
#> mpg cyl disp hp drat wt qsec vs am gear carb
#> 1 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1
#> 2 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2
#> 3 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2
#> 4 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4
#> 5 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2
#> 6 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1
#> 7 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2
#> 8 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2
#> 9 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4
#> 10 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6
#> 11 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8
#> 12 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2
#>
# import and rbind all worksheets, the return value is a data frame
import_list(xlsx_file, rbind = TRUE)
#> mpg cyl disp hp drat wt qsec vs am gear carb _file
#> 1 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4 1
#> 2 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4 1
#> 3 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1 1
#> 4 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1 1
#> 5 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2 1
#> 6 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1 1
#> 7 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4 1
#> 8 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2 1
#> 9 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2 1
#> 10 19.2 6 167.6 123 3.92 3.440 18.30 1 0 4 4 1
#> 11 17.8 6 167.6 123 3.92 3.440 18.90 1 0 4 4 2
#> 12 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3 2
#> 13 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3 2
#> 14 15.2 8 275.8 180 3.07 3.780 18.00 0 0 3 3 2
#> 15 10.4 8 472.0 205 2.93 5.250 17.98 0 0 3 4 2
#> 16 10.4 8 460.0 215 3.00 5.424 17.82 0 0 3 4 2
#> 17 14.7 8 440.0 230 3.23 5.345 17.42 0 0 3 4 2
#> 18 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1 2
#> 19 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2 2
#> 20 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1 2
#> 21 21.5 4 120.1 97 3.70 2.465 20.01 1 0 3 1 3
#> 22 15.5 8 318.0 150 2.76 3.520 16.87 0 0 3 2 3
#> 23 15.2 8 304.0 150 3.15 3.435 17.30 0 0 3 2 3
#> 24 13.3 8 350.0 245 3.73 3.840 15.41 0 0 3 4 3
#> 25 19.2 8 400.0 175 3.08 3.845 17.05 0 0 3 2 3
#> 26 27.3 4 79.0 66 4.08 1.935 18.90 1 1 4 1 3
#> 27 26.0 4 120.3 91 4.43 2.140 16.70 0 1 5 2 3
#> 28 30.4 4 95.1 113 3.77 1.513 16.90 1 1 5 2 3
#> 29 15.8 8 351.0 264 4.22 3.170 14.50 0 1 5 4 3
#> 30 19.7 6 145.0 175 3.62 2.770 15.50 0 1 5 6 3
#> 31 15.0 8 301.0 335 3.54 3.570 14.60 0 1 5 8 3
#> 32 21.4 4 121.0 109 4.11 2.780 18.60 1 1 4 2 3