✨ fwiffer ✨

Getting column positions and widths for parsing fixed width file formats is painful. Tape measures are dangerous and useless for measuring column widths. If your data is stored in fixed width files but readr::read_fwf() can’t guess the column widths, then you need a new tool.

Installation

You can install the released version of fwiffer from GitHub

# install.packages("devtools")
devtools::install_github("gadenbuie/fwiffer")

Fixed Width Files Made Easy 😅

Open your fixed-width data file and use Command + Alt + click to add cursors at the start of each column. They don’t have to be on the same line or in the same order!

Then choose the RStudio addin of your choice:

• Cursors to Column Widths

• Cursors to Column Start/End

And get back the readr::read_fwf() code you need. Edit the names in col_names and move on with your day!

Column Widths

col_widths <- c(20, 10, 11)
col_names <- c("X01", "X02", "X03")
readr::read_fwf("inst/fwf-sample.txt", readr::fwf_widths(col_widths, col_names))

## Parsed with column specification:
## cols(
##   X01 = col_character(),
##   X02 = col_character(),
##   X03 = col_character()
## )

## # A tibble: 3 x 3
##   X01           X02   X03        
##   <chr>         <chr> <chr>      
## 1 John Smith    WA    418-Y11-411
## 2 Mary Hartford CA    319-Z19-434
## 3 Evan Nolan    IL    219-532-c30

Column Start/End

col_starts <- c(1, 21, 31)
col_ends <- c(20, 30, 42)
col_names <- c("X01", "X02", "X03")
readr::read_fwf("inst/fwf-sample.txt", readr::fwf_positions(col_starts, col_ends, col_names))

## Parsed with column specification:
## cols(
##   X01 = col_character(),
##   X02 = col_character(),
##   X03 = col_character()
## )

## # A tibble: 3 x 3
##   X01           X02   X03         
##   <chr>         <chr> <chr>       
## 1 John Smith    WA    418-Y11-4111
## 2 Mary Hartford CA    319-Z19-4341
## 3 Evan Nolan    IL    219-532-c301