Spreadsheets

Introduction

So far, you have learned about importing data from plain text files, e.g., .csv and .tsv files. Sometimes you need to analyze data that lives in a spreadsheet. This chapter will introduce you to tools for working with data in Excel spreadsheets and Google Sheets. This will build on much of what you’ve learned in #chp-data-import, but we will also discuss additional considerations and complexities when working with data from spreadsheets.

If you or your collaborators are using spreadsheets for organizing data, we strongly recommend reading the paper “Data Organization in Spreadsheets” by Karl Broman and Kara Woo: https://doi.org/10.1080/00031305.2017.1375989. The best practices presented in this paper will save you much headache when you import data from a spreadsheet into R to analyze and visualize.

Excel

Prerequisites

In this section, you’ll learn how to load data from Excel spreadsheets in R with the readxl package. This package is non-core tidyverse, so you need to load it explicitly, but it is installed automatically when you install the tidyverse package.

library(readxl)
library(tidyverse)

openxlsx, xlsx, and XLConnect can also be used for reading data from and writing data to Excel spreadsheets. We will discuss openxlsx in #sec-writing-to-excel. The latter two packages require Java installed on your machine and the rJava package. Due to potential challenges with installation, we recommend using alternative packages we’re introducing in this chapter.

Getting started

Most of readxl’s functions allow you to load Excel spreadsheets into R:

  • read_xls() reads Excel files with xls format.
  • read_xlsx() read Excel files with xlsx format.
  • read_excel() can read files with both xls and xlsx format. It guesses the file type based on the input.

These functions all have similar syntax just like other functions we have previously introduced for reading other types of files, e.g. read_csv(), read_table(), etc. For the rest of the chapter we will focus on using read_excel().

Reading spreadsheets

#fig-students-excel shows what the spreadsheet we’re going to read into R looks like in Excel.

A look at the students spreadsheet in Excel. The spreadsheet contains information on 6 students, their ID, full name, favourite food, meal plan, and age.

Spreadsheet called students.xlsx in Excel.

The first argument to read_excel() is the path to the file to read.

students <- read_excel("data/students.xlsx")

read_excel() will read the file in as a tibble.

students
#> # A tibble: 6 × 5
#>   `Student ID` `Full Name`      favourite.food     mealPlan            AGE  
#>          <dbl> <chr>            <chr>              <chr>               <chr>
#> 1            1 Sunil Huffmann   Strawberry yoghurt Lunch only          4    
#> 2            2 Barclay Lynn     French fries       Lunch only          5    
#> 3            3 Jayendra Lyne    N/A                Breakfast and lunch 7    
#> 4            4 Leon Rossini     Anchovies          Lunch only          <NA> 
#> 5            5 Chidiegwu Dunkel Pizza              Breakfast and lunch five 
#> 6            6 Güvenç Attila    Ice cream          Lunch only          6

We have six students in the data and five variables on each student. However there are a few things we might want to address in this dataset:

  1. The column names are all over the place. You can provide column names that follow a consistent format; we recommend snake_case using the col_names argument.

    read_excel(
      "data/students.xlsx",
      col_names = c("student_id", "full_name", "favourite_food", "meal_plan", "age")
    )
    #> # A tibble: 7 × 5
    #>   student_id full_name        favourite_food     meal_plan           age  
    #>   <chr>      <chr>            <chr>              <chr>               <chr>
    #> 1 Student ID Full Name        favourite.food     mealPlan            AGE  
    #> 2 1          Sunil Huffmann   Strawberry yoghurt Lunch only          4    
    #> 3 2          Barclay Lynn     French fries       Lunch only          5    
    #> 4 3          Jayendra Lyne    N/A                Breakfast and lunch 7    
    #> 5 4          Leon Rossini     Anchovies          Lunch only          <NA> 
    #> 6 5          Chidiegwu Dunkel Pizza              Breakfast and lunch five 
    #> 7 6          Güvenç Attila    Ice cream          Lunch only          6

    Unfortunately, this didn’t quite do the trick. We now have the variable names we want, but what was previously the header row now shows up as the first observation in the data. You can explicitly skip that row using the skip argument.

    read_excel(
      "data/students.xlsx",
      col_names = c("student_id", "full_name", "favourite_food", "meal_plan", "age"),
      skip = 1
    )
    #> # A tibble: 6 × 5
    #>   student_id full_name        favourite_food     meal_plan           age  
    #>        <dbl> <chr>            <chr>              <chr>               <chr>
    #> 1          1 Sunil Huffmann   Strawberry yoghurt Lunch only          4    
    #> 2          2 Barclay Lynn     French fries       Lunch only          5    
    #> 3          3 Jayendra Lyne    N/A                Breakfast and lunch 7    
    #> 4          4 Leon Rossini     Anchovies          Lunch only          <NA> 
    #> 5          5 Chidiegwu Dunkel Pizza              Breakfast and lunch five 
    #> 6          6 Güvenç Attila    Ice cream          Lunch only          6
  2. In the favourite_food column, one of the observations is N/A, which stands for “not available” but it’s currently not recognized as an NA (note the contrast between this N/A and the age of the fourth student in the list). You can specify which character strings should be recognized as NAs with the na argument. By default, only "" (empty string, or, in the case of reading from a spreadsheet, an empty cell or a cell with the formula =NA()) is recognized as an NA.

    read_excel(
      "data/students.xlsx",
      col_names = c("student_id", "full_name", "favourite_food", "meal_plan", "age"),
      skip = 1,
      na = c("", "N/A")
    )
    #> # A tibble: 6 × 5
    #>   student_id full_name        favourite_food     meal_plan           age  
    #>        <dbl> <chr>            <chr>              <chr>               <chr>
    #> 1          1 Sunil Huffmann   Strawberry yoghurt Lunch only          4    
    #> 2          2 Barclay Lynn     French fries       Lunch only          5    
    #> 3          3 Jayendra Lyne    <NA>               Breakfast and lunch 7    
    #> 4          4 Leon Rossini     Anchovies          Lunch only          <NA> 
    #> 5          5 Chidiegwu Dunkel Pizza              Breakfast and lunch five 
    #> 6          6 Güvenç Attila    Ice cream          Lunch only          6
  3. One other remaining issue is that age is read in as a character variable, but it really should be numeric. Just like with read_csv() and friends for reading data from flat files, you can supply a col_types argument to read_excel() and specify the column types for the variables you read in. The syntax is a bit different, though. Your options are "skip", "guess", "logical", "numeric", "date", "text" or "list".

    read_excel(
      "data/students.xlsx",
      col_names = c("student_id", "full_name", "favourite_food", "meal_plan", "age"),
      skip = 1,
      na = c("", "N/A"),
      col_types = c("numeric", "text", "text", "text", "numeric")
    )
    #> Warning: Expecting numeric in E6 / R6C5: got 'five'
    #> # A tibble: 6 × 5
    #>   student_id full_name        favourite_food     meal_plan             age
    #>        <dbl> <chr>            <chr>              <chr>               <dbl>
    #> 1          1 Sunil Huffmann   Strawberry yoghurt Lunch only              4
    #> 2          2 Barclay Lynn     French fries       Lunch only              5
    #> 3          3 Jayendra Lyne    <NA>               Breakfast and lunch     7
    #> 4          4 Leon Rossini     Anchovies          Lunch only             NA
    #> 5          5 Chidiegwu Dunkel Pizza              Breakfast and lunch    NA
    #> 6          6 Güvenç Attila    Ice cream          Lunch only              6

    However, this didn’t quite produce the desired result either. By specifying that age should be numeric, we have turned the one cell with the non-numeric entry (which had the value five) into an NA. In this case, we should read age in as "text" and then make the change once the data is loaded in R.

    students <- read_excel(
      "data/students.xlsx",
      col_names = c("student_id", "full_name", "favourite_food", "meal_plan", "age"),
      skip = 1,
      na = c("", "N/A"),
      col_types = c("numeric", "text", "text", "text", "text")
    )
    
    students <- students |>
      mutate(
        age = if_else(age == "five", "5", age),
        age = parse_number(age)
      )
    
    students
    #> # A tibble: 6 × 5
    #>   student_id full_name        favourite_food     meal_plan             age
    #>        <dbl> <chr>            <chr>              <chr>               <dbl>
    #> 1          1 Sunil Huffmann   Strawberry yoghurt Lunch only              4
    #> 2          2 Barclay Lynn     French fries       Lunch only              5
    #> 3          3 Jayendra Lyne    <NA>               Breakfast and lunch     7
    #> 4          4 Leon Rossini     Anchovies          Lunch only             NA
    #> 5          5 Chidiegwu Dunkel Pizza              Breakfast and lunch     5
    #> 6          6 Güvenç Attila    Ice cream          Lunch only              6

It took us multiple steps and trial-and-error to load the data in exactly the format we want, and this is not unexpected. Data science is an iterative process, and the process of iteration can be even more tedious when reading data in from spreadsheets compared to other plain text, rectangular data files because humans tend to input data into spreadsheets and use them not just for data storage but also for sharing and communication.

There is no way to know exactly what the data will look like until you load it and take a look at it. Well, there is one way, actually. You can open the file in Excel and take a peek. If you’re going to do so, we recommend making a copy of the Excel file to open and browse interactively while leaving the original data file untouched and reading into R from the untouched file. This will ensure you don’t accidentally overwrite anything in the spreadsheet while inspecting it. You should also not be afraid of doing what we did here: load the data, take a peek, make adjustments to your code, load it again, and repeat until you’re happy with the result.

Reading worksheets

An important feature that distinguishes spreadsheets from flat files is the notion of multiple sheets, called worksheets. #fig-penguins-islands shows an Excel spreadsheet with multiple worksheets. The data come from the palmerpenguins package. Each worksheet contains information on penguins from a different island where data were collected.

A look at the penguins spreadsheet in Excel. The spreadsheet contains has three worksheets: Torgersen Island, Biscoe Island, and Dream Island.

Spreadsheet called penguins.xlsx in Excel containing three worksheets.

You can read a single worksheet from a spreadsheet with the sheet argument in read_excel().

read_excel("data/penguins.xlsx", sheet = "Torgersen Island")
#> # A tibble: 52 × 8
#>   species island   bill_length_mm bill_depth_mm flipper_length_mm body_mass_g
#>   <chr>   <chr>    <chr>          <chr>         <chr>             <chr>      
#> 1 Adelie  Torgers… 39.1           18.7          181               3750       
#> 2 Adelie  Torgers… 39.5           17.399999999… 186               3800       
#> 3 Adelie  Torgers… 40.2999999999… 18            195               3250       
#> 4 Adelie  Torgers… NA             NA            NA                NA         
#> 5 Adelie  Torgers… 36.7000000000… 19.3          193               3450       
#> 6 Adelie  Torgers… 39.2999999999… 20.6          190               3650       
#> # … with 46 more rows, and 2 more variables: sex <chr>, year <dbl>

Some variables that appear to contain numerical data are read in as characters due to the character string "NA" not being recognized as a true NA.

penguins_torgersen <- read_excel("data/penguins.xlsx", sheet = "Torgersen Island", na = "NA")

penguins_torgersen
#> # A tibble: 52 × 8
#>   species island   bill_length_mm bill_depth_mm flipper_length_mm body_mass_g
#>   <chr>   <chr>             <dbl>         <dbl>             <dbl>       <dbl>
#> 1 Adelie  Torgers…           39.1          18.7               181        3750
#> 2 Adelie  Torgers…           39.5          17.4               186        3800
#> 3 Adelie  Torgers…           40.3          18                 195        3250
#> 4 Adelie  Torgers…           NA            NA                  NA          NA
#> 5 Adelie  Torgers…           36.7          19.3               193        3450
#> 6 Adelie  Torgers…           39.3          20.6               190        3650
#> # … with 46 more rows, and 2 more variables: sex <chr>, year <dbl>

Alternatively, you can use excel_sheets() to get information on all worksheets in an Excel spreadsheet, and then read the one(s) you’re interested in.

excel_sheets("data/penguins.xlsx")
#> [1] "Torgersen Island" "Biscoe Island"    "Dream Island"

Once you know the names of the worksheets, you can read them in individually with read_excel().

penguins_biscoe <- read_excel("data/penguins.xlsx", sheet = "Biscoe Island", na = "NA")
penguins_dream  <- read_excel("data/penguins.xlsx", sheet = "Dream Island", na = "NA")

In this case the full penguins dataset is spread across three worksheets in the spreadsheet. Each worksheet has the same number of columns but different numbers of rows.

dim(penguins_torgersen)
#> [1] 52  8
dim(penguins_biscoe)
#> [1] 168   8
dim(penguins_dream)
#> [1] 124   8

We can put them together with bind_rows().

penguins <- bind_rows(penguins_torgersen, penguins_biscoe, penguins_dream)
penguins
#> # A tibble: 344 × 8
#>   species island   bill_length_mm bill_depth_mm flipper_length_mm body_mass_g
#>   <chr>   <chr>             <dbl>         <dbl>             <dbl>       <dbl>
#> 1 Adelie  Torgers…           39.1          18.7               181        3750
#> 2 Adelie  Torgers…           39.5          17.4               186        3800
#> 3 Adelie  Torgers…           40.3          18                 195        3250
#> 4 Adelie  Torgers…           NA            NA                  NA          NA
#> 5 Adelie  Torgers…           36.7          19.3               193        3450
#> 6 Adelie  Torgers…           39.3          20.6               190        3650
#> # … with 338 more rows, and 2 more variables: sex <chr>, year <dbl>

In #chp-iteration we’ll talk about ways of doing this sort of task without repetitive code.

Reading part of a sheet

Since many use Excel spreadsheets for presentation as well as for data storage, it’s quite common to find cell entries in a spreadsheet that are not part of the data you want to read into R. #fig-deaths-excel shows such a spreadsheet: in the middle of the sheet is what looks like a data frame but there is extraneous text in cells above and below the data.

A look at the deaths spreadsheet in Excel. The spreadsheet has four rows on top that contain non-data information; the text 'For the same of consistency in the data layout, which is really a beautiful thing, I will keep making notes up here.' is spread across cells in these top four rows. Then, there is a data frame that includes information on deaths of 10 famous people, including their names, professions, ages, whether they have kids or not, date of birth and death. At the bottom, there are four more rows of non-data information; the text 'This has been really fun, but we're signing off now!' is spread across cells in these bottom four rows.

Spreadsheet called deaths.xlsx in Excel.

This spreadsheet is one of the example spreadsheets provided in the readxl package. You can use the readxl_example() function to locate the spreadsheet on your system in the directory where the package is installed. This function returns the path to the spreadsheet, which you can use in read_excel() as usual.

deaths_path <- readxl_example("deaths.xlsx")
deaths <- read_excel(deaths_path)
#> New names:
#> • `` -> `...2`
#> • `` -> `...3`
#> • `` -> `...4`
#> • `` -> `...5`
#> • `` -> `...6`
deaths
#> # A tibble: 18 × 6
#>   `Lots of people`             ...2       ...3  ...4     ...5          ...6  
#>   <chr>                        <chr>      <chr> <chr>    <chr>         <chr> 
#> 1 simply cannot resist writing <NA>       <NA>  <NA>     <NA>          some …
#> 2 at                           the        top   <NA>     of            their…
#> 3 or                           merging    <NA>  <NA>     <NA>          cells 
#> 4 Name                         Profession Age   Has kids Date of birth Date …
#> 5 David Bowie                  musician   69    TRUE     17175         42379 
#> 6 Carrie Fisher                actor      60    TRUE     20749         42731 
#> # … with 12 more rows

The top three rows and the bottom four rows are not part of the data frame.

We could skip the top three rows with skip. Note that we set skip = 4 since the fourth row contains column names, not the data.

read_excel(deaths_path, skip = 4)
#> # A tibble: 14 × 6
#>   Name        Profession Age   `Has kids` `Date of birth`     `Date of death`
#>   <chr>       <chr>      <chr> <chr>      <dttm>              <chr>          
#> 1 David Bowie musician   69    TRUE       1947-01-08 00:00:00 42379          
#> 2 Carrie Fis… actor      60    TRUE       1956-10-21 00:00:00 42731          
#> 3 Chuck Berry musician   90    TRUE       1926-10-18 00:00:00 42812          
#> 4 Bill Paxton actor      61    TRUE       1955-05-17 00:00:00 42791          
#> 5 Prince      musician   57    TRUE       1958-06-07 00:00:00 42481          
#> 6 Alan Rickm… actor      69    FALSE      1946-02-21 00:00:00 42383          
#> # … with 8 more rows

We could also set n_max to omit the extraneous rows at the bottom.

read_excel(deaths_path, skip = 4, n_max = 10)
#> # A tibble: 10 × 6
#>   Name    Profession   Age `Has kids` `Date of birth`     `Date of death`    
#>   <chr>   <chr>      <dbl> <lgl>      <dttm>              <dttm>             
#> 1 David … musician      69 TRUE       1947-01-08 00:00:00 2016-01-10 00:00:00
#> 2 Carrie… actor         60 TRUE       1956-10-21 00:00:00 2016-12-27 00:00:00
#> 3 Chuck … musician      90 TRUE       1926-10-18 00:00:00 2017-03-18 00:00:00
#> 4 Bill P… actor         61 TRUE       1955-05-17 00:00:00 2017-02-25 00:00:00
#> 5 Prince  musician      57 TRUE       1958-06-07 00:00:00 2016-04-21 00:00:00
#> 6 Alan R… actor         69 FALSE      1946-02-21 00:00:00 2016-01-14 00:00:00
#> # … with 4 more rows

Another approach is using cell ranges. In Excel, the top left cell is A1. As you move across columns to the right, the cell label moves down the alphabet, i.e. B1, C1, etc. And as you move down a column, the number in the cell label increases, i.e. A2, A3, etc.

The data we want to read in starts in cell A5 and ends in cell F15. In spreadsheet notation, this is A5:F15.

  • Supply this information to the range argument:

    read_excel(deaths_path, range = "A5:F15")
  • Specify rows:

    read_excel(deaths_path, range = cell_rows(c(5, 15)))

Data types

In CSV files, all values are strings. This is not particularly true to the data, but it is simple: everything is a string.

The underlying data in Excel spreadsheets is more complex. A cell can be one of five things:

  • A boolean, like TRUE, FALSE, or NA

  • A number, like “10” or “10.5”

  • A datetime, which can also include time like “11/1/21” or “11/1/21 3:00 PM”

  • A text string, like “ten”

When working with spreadsheet data, it’s important to keep in mind that how the underlying data is stored can be very different than what you see in the cell. For example, Excel has no notion of an integer. All numbers are stored as floating points, but you can choose to display the data with a customizable number of decimal points. Similarly, dates are actually stored as numbers, specifically the number of seconds since January 1, 1970. You can customize how you display the date by applying formatting in Excel. Confusingly, it’s also possible to have something that looks like a number but is actually a string (e.g. type '10 into a cell in Excel).

These differences between how the underlying data are stored vs. how they’re displayed can cause surprises when the data are loaded into R. By default readxl will guess the data type in a given column. A recommended workflow is to let readxl guess the column types, confirm that you’re happy with the guessed column types, and if not, go back and re-import specifying col_types as shown in #sec-reading-spreadsheets.

Another challenge is when you have a column in your Excel spreadsheet that has a mix of these types, e.g. some cells are numeric, others text, others dates. When importing the data into R readxl has to make some decisions. In these cases you can set the type for this column to "list", which will load the column as a list of length 1 vectors, where the type of each element of the vector is guessed.

Data not in cell values

tidyxl is useful for importing non-tabular data from Excel files into R. For example, tidyxl doesn’t coerce a pivot table into a data frame. See https://nacnudus.github.io/spreadsheet-munging-strategies/ for more on strategies for working with non-tabular data from Excel.

Writing to Excel

Let’s create a small data frame that we can then write out. Note that item is a factor and quantity is an integer.

bake_sale <- tibble(
  item     = factor(c("brownie", "cupcake", "cookie")),
  quantity = c(10, 5, 8)
)

bake_sale
#> # A tibble: 3 × 2
#>   item    quantity
#>   <fct>      <dbl>
#> 1 brownie       10
#> 2 cupcake        5
#> 3 cookie         8

You can write data back to disk as an Excel file using the write_xlsx() from the writexl package.

library(writexl)
write_xlsx(bake_sale, path = "data/bake-sale.xlsx")

#fig-bake-sale-excel shows what the data looks like in Excel. Note that column names are included and bolded. These can be turned off by setting col_names and format_headers arguments to FALSE.

Bake sale data frame created earlier in Excel.

Spreadsheet called bake_sale.xlsx in Excel.

Just like reading from a CSV, information on data type is lost when we read the data back in. This makes Excel files unreliable for caching interim results as well. For alternatives, see #sec-writing-to-a-file.

read_excel("data/bake-sale.xlsx")
#> # A tibble: 3 × 2
#>   item    quantity
#>   <chr>      <dbl>
#> 1 brownie       10
#> 2 cupcake        5
#> 3 cookie         8

Formatted output

The readxl package is a light-weight solution for writing a simple Excel spreadsheet, but if you’re interested in additional features like writing to sheets within a spreadsheet and styling, you will want to use the openxlsx package. Note that this package is not part of the tidyverse so the functions and workflows may feel unfamiliar. For example, function names are camelCase, multiple functions can’t be composed in pipelines, and arguments are in a different order than they tend to be in the tidyverse. However, this is ok. As your R learning and usage expands outside of this book you will encounter lots of different styles used in various R packages that you might need to use to accomplish specific goals in R. A good way of familiarizing yourself with the coding style used in a new package is to run the examples provided in function documentation to get a feel for the syntax and the output formats as well as reading any vignettes that might come with the package.

Below we show how to write a spreadsheet with three sheets, one for each species of penguins in the penguins data frame.

library(openxlsx)
library(palmerpenguins)

# Create a workbook (spreadsheet)
penguins_species <- createWorkbook()

# Add three sheets to the spreadsheet
addWorksheet(penguins_species, sheetName = "Adelie")
addWorksheet(penguins_species, sheetName = "Gentoo")
addWorksheet(penguins_species, sheetName = "Chinstrap")

# Write data to each sheet
writeDataTable(
  penguins_species, 
  sheet = "Adelie", 
  x = penguins |> filter(species == "Adelie")
)
writeDataTable(
  penguins_species, 
  sheet = "Gentoo", 
  x = penguins |> filter(species == "Gentoo")
)
writeDataTable(
  penguins_species, 
  sheet = "Chinstrap", 
  x = penguins |> filter(species == "Chinstrap")
)

This creates a workbook object:

penguins_species
#> A Workbook object.
#>  
#> Worksheets:
#>  Sheet 1: "Adelie"
#>  
#> 
#>  Sheet 2: "Gentoo"
#>  
#> 
#>  Sheet 3: "Chinstrap"
#>  
#> 
#>  
#>  Worksheet write order: 1, 2, 3
#>  Active Sheet 1: "Adelie" 
#>  Position: 1

And we can write this to this with saveWorkbook().

saveWorkbook(penguins_species, "data/penguins-species.xlsx")

The resulting spreadsheet is shown in #fig-penguins-species. By default, openxlsx formats the data as an Excel table.

A look at the penguins spreadsheet in Excel. The spreadsheet contains has three sheets: Torgersen Island, Biscoe Island, and Dream Island.

Spreadsheet called penguins.xlsx in Excel.

See https://ycphs.github.io/openxlsx/articles/Formatting.html for an extensive discussion on further formatting functionality for data written from R to Excel with openxlsx.

Exercises

  1. In an Excel file, create the following dataset and save it as survey.xlsx. Alternatively, you can download it as an Excel file from here.

    A spreadsheet with 3 columns (group, subgroup, and id) and 12 rows. The group column has two values: 1 (spanning 7 merged rows) and 2 (spanning 5 merged rows). The subgroup column has four values: A (spanning 3 merged rows), B (spanning 4 merged rows), A (spanning 2 merged rows), and B (spanning 3 merged rows). The id column has twelve values, numbers 1 through 12.

    Then, read it into R, with survey_id as a character variable and n_pets as a numerical variable. Hint: You will need to convert “none” to 0.

    #> # A tibble: 6 × 2
    #>   survey_id n_pets
    #>       <dbl>  <dbl>
    #> 1         1      0
    #> 2         2      1
    #> 3         3     NA
    #> 4         4      2
    #> 5         5      2
    #> 6         6     NA
  2. In another Excel file, create the following dataset and save it as roster.xlsx. Alternatively, you can download it as an Excel file from here.

    A spreadsheet with 3 columns (group, subgroup, and id) and 12 rows. The group column has two values: 1 (spanning 7 merged rows) and 2 (spanning 5 merged rows). The subgroup column has four values: A (spanning 3 merged rows), B (spanning 4 merged rows), A (spanning 2 merged rows), and B (spanning 3 merged rows). The id column has twelve values, numbers 1 through 12.

    Then, read it into R. The resulting data frame should be called roster and should look like the following.

    #> # A tibble: 12 × 3
    #>    group subgroup    id
    #>    <dbl> <chr>    <dbl>
    #>  1     1 A            1
    #>  2     1 A            2
    #>  3     1 A            3
    #>  4     1 B            4
    #>  5     1 B            5
    #>  6     1 B            6
    #>  7     1 B            7
    #>  8     2 A            8
    #>  9     2 A            9
    #> 10     2 B           10
    #> 11     2 B           11
    #> 12     2 B           12
  3. In a new Excel file, create the following dataset and save it as sales.xlsx. Alternatively, you can download it as an Excel file from here.

    A spreadsheet with 2 columns and 13 rows. The first two rows have text containing information about the sheet. Row 1 says "This file contains information on sales". Row 2 says "Data are organized by brand name, and for each brand, we have the ID number for the item sold, and how many are sold.". Then there are two empty rows, and then 9 rows of data.

    a. Read sales.xlsx in and save as sales. The data frame should look like the following, with id and n as column names and with 9 rows.

    #> # A tibble: 9 × 2
    #>   id      n    
    #>   <chr>   <chr>
    #> 1 Brand 1 n    
    #> 2 1234    8    
    #> 3 8721    2    
    #> 4 1822    3    
    #> 5 Brand 2 n    
    #> 6 3333    1    
    #> 7 2156    3    
    #> 8 3987    6    
    #> 9 3216    5

    b. Modify sales further to get it into the following tidy format with three columns (brand, id, and n) and 7 rows of data. Note that id and n are numeric, brand is a character variable.

    #> # A tibble: 7 × 3
    #>   brand      id     n
    #>   <chr>   <dbl> <dbl>
    #> 1 Brand 1  1234     8
    #> 2 Brand 1  8721     2
    #> 3 Brand 1  1822     3
    #> 4 Brand 2  3333     1
    #> 5 Brand 2  2156     3
    #> 6 Brand 2  3987     6
    #> 7 Brand 2  3216     5
  4. Recreate the bake_sale data frame, write it out to an Excel file using the write.xlsx() function from the openxlsx package.

  5. In #chp-data-import you learned about the janitor::clean_names() function to turn columns names into snake case. Read the students.xlsx file that we introduced earlier in this section and use this function to “clean” the column names.

  6. What happens if you try to read in a file with .xlsx extension with read_xls()?

Google Sheets

Prerequisites

This section will also focus on spreadsheets, but this time you’ll be loading data from a Google Sheet with the googlesheets4 package. This package is non-core tidyverse as well, you need to load it explicitly.

library(googlesheets4)
library(tidyverse)

A quick note about the name of the package: googlesheets4 uses v4 of the Sheets API v4 to provide an R interface to Google Sheets, hence the name.

Getting started

The main function of the googlesheets4 package is read_sheet(), which reads a Google Sheet from a URL or a file id. This function also goes by the name range_read().

You can also create a brand new sheet with gs4_create() or write to an existing sheet with sheet_write() and friends.

In this section we’ll work with the same datasets as the ones in the Excel section to highlight similarities and differences between workflows for reading data from Excel and Google Sheets. readxl and googlesheets4 packages are both designed to mimic the functionality of the readr package, which provides the read_csv() function you’ve seen in #chp-data-import. Therefore, many of the tasks can be accomplished with simply swapping out read_excel() for read_sheet(). However you’ll also see that Excel and Google Sheets don’t behave in exactly the same way, therefore other tasks may require further updates to the function calls.

Read sheets

#fig-students-googlesheets shows what the spreadsheet we’re going to read into R looks like in Google Sheets. This is the same dataset as in #fig-students-excel, except it’s stored in a Google Sheet instead of Excel.

A look at the students spreadsheet in Google Sheets. The spreadsheet contains information on 6 students, their ID, full name, favourite food, meal plan, and age.

Google Sheet called students in a browser window.

The first argument to read_sheet() is the URL of the file to read. You can also access this file via https://pos.it/r4ds-students, however note that at the time of writing this book you can’t read a sheet directly from a short link.

students <- read_sheet("https://docs.google.com/spreadsheets/d/1V1nPp1tzOuutXFLb3G9Eyxi3qxeEhnOXUzL5_BcCQ0w/edit?usp=sharing")
#> ✔ Reading from "students".
#> ✔ Range 'Sheet1'.

read_sheet() will read the file in as a tibble.

students
#> # A tibble: 6 × 5
#>   `Student ID` `Full Name`      favourite.food     mealPlan            AGE   
#>          <dbl> <chr>            <chr>              <chr>               <list>
#> 1            1 Sunil Huffmann   Strawberry yoghurt Lunch only          <dbl> 
#> 2            2 Barclay Lynn     French fries       Lunch only          <dbl> 
#> 3            3 Jayendra Lyne    N/A                Breakfast and lunch <dbl> 
#> 4            4 Leon Rossini     Anchovies          Lunch only          <NULL>
#> 5            5 Chidiegwu Dunkel Pizza              Breakfast and lunch <chr> 
#> 6            6 Güvenç Attila    Ice cream          Lunch only          <dbl>

Just like we did with read_excel(), we can supply column names, NA strings, and column types to read_sheet().

students <- read_sheet(
  "https://docs.google.com/spreadsheets/d/1V1nPp1tzOuutXFLb3G9Eyxi3qxeEhnOXUzL5_BcCQ0w/edit?usp=sharing",
  col_names = c("student_id", "full_name", "favourite_food", "meal_plan", "age"),
  skip = 1,
  na = c("", "N/A"),
  col_types = c("dcccc")
) |>
  mutate(
    age = if_else(age == "five", "5", age),
    age = parse_number(age)
  )
#> ✔ Reading from "students".
#> ✔ Range '2:10000000'.

students
#> # A tibble: 6 × 5
#>   student_id full_name        favourite_food     meal_plan             age
#>        <dbl> <chr>            <chr>              <chr>               <dbl>
#> 1          1 Sunil Huffmann   Strawberry yoghurt Lunch only              4
#> 2          2 Barclay Lynn     French fries       Lunch only              5
#> 3          3 Jayendra Lyne    <NA>               Breakfast and lunch     7
#> 4          4 Leon Rossini     Anchovies          Lunch only             NA
#> 5          5 Chidiegwu Dunkel Pizza              Breakfast and lunch     5
#> 6          6 Güvenç Attila    Ice cream          Lunch only              6

Note that we defined column types a bit differently here, using short codes. For example, “dcccc” stands for “double, character, character, character, character”.

It’s also possible to read individual sheets from Google Sheets as well. Let’s read the penguins Google Sheet at https://pos.it/r4ds-penguins, and specifically the “Torgersen Island” sheet in it.

read_sheet("https://docs.google.com/spreadsheets/d/1aFu8lnD_g0yjF5O-K6SFgSEWiHPpgvFCF0NY9D6LXnY/edit?usp=sharing", sheet = "Torgersen Island")
#> ✔ Reading from "penguins".
#> ✔ Range ''Torgersen Island''.
#> # A tibble: 52 × 8
#>   species island   bill_length_mm bill_depth_mm flipper_length_mm body_mass_g
#>   <chr>   <chr>    <list>         <list>        <list>            <list>     
#> 1 Adelie  Torgers… <dbl [1]>      <dbl [1]>     <dbl [1]>         <dbl [1]>  
#> 2 Adelie  Torgers… <dbl [1]>      <dbl [1]>     <dbl [1]>         <dbl [1]>  
#> 3 Adelie  Torgers… <dbl [1]>      <dbl [1]>     <dbl [1]>         <dbl [1]>  
#> 4 Adelie  Torgers… <chr [1]>      <chr [1]>     <chr [1]>         <chr [1]>  
#> 5 Adelie  Torgers… <dbl [1]>      <dbl [1]>     <dbl [1]>         <dbl [1]>  
#> 6 Adelie  Torgers… <dbl [1]>      <dbl [1]>     <dbl [1]>         <dbl [1]>  
#> # … with 46 more rows, and 2 more variables: sex <chr>, year <dbl>

You can obtain a list of all sheets within a Google Sheet with sheet_names():

sheet_names("https://docs.google.com/spreadsheets/d/1aFu8lnD_g0yjF5O-K6SFgSEWiHPpgvFCF0NY9D6LXnY/edit?usp=sharing")
#> [1] "Torgersen Island" "Biscoe Island"    "Dream Island"

Finally, just like with read_excel(), we can read in a portion of a Google Sheet by defining a range in read_sheet(). Note that we’re also using the gs4_example() function below to locate an example Google Sheet that comes with the googlesheets4 package.

deaths_url <- gs4_example("deaths")
deaths <- read_sheet(deaths_url, range = "A5:F15")
#> ✔ Reading from "deaths".
#> ✔ Range 'A5:F15'.
deaths
#> # A tibble: 10 × 6
#>   Name    Profession   Age `Has kids` `Date of birth`     `Date of death`    
#>   <chr>   <chr>      <dbl> <lgl>      <dttm>              <dttm>             
#> 1 David … musician      69 TRUE       1947-01-08 00:00:00 2016-01-10 00:00:00
#> 2 Carrie… actor         60 TRUE       1956-10-21 00:00:00 2016-12-27 00:00:00
#> 3 Chuck … musician      90 TRUE       1926-10-18 00:00:00 2017-03-18 00:00:00
#> 4 Bill P… actor         61 TRUE       1955-05-17 00:00:00 2017-02-25 00:00:00
#> 5 Prince  musician      57 TRUE       1958-06-07 00:00:00 2016-04-21 00:00:00
#> 6 Alan R… actor         69 FALSE      1946-02-21 00:00:00 2016-01-14 00:00:00
#> # … with 4 more rows

Write sheets

You can write from R to Google Sheets with write_sheet():

write_sheet(bake_sale, ss = "bake-sale")

If you’d like to write your data to a specific (work)sheet inside a Google Sheet, you can specify that with the sheet argument as well.

write_sheet(bake_sale, ss = "bake-sale", sheet = "Sales")

Authentication

While you can read from a public Google Sheet without authenticating with your Google account, reading a private sheet or writing to a sheet requires authentication so that googlesheets4 can view and manage your Google Sheets.

When you attempt to read in a sheet that requires authentication, googlesheets4 will direct you to a web browser with a prompt to sign in to your Google account and grant permission to operate on your behalf with Google Sheets. However, if you want to specify a specific Google account, authentication scope, etc. you can do so with gs4_auth(), e.g. gs4_auth(email = "mine@example.com"), which will force the use of a token associated with a specific email. For further authentication details, we recommend reading the documentation googlesheets4 auth vignette: https://googlesheets4.tidyverse.org/articles/auth.html.

Exercises

  1. Read the students dataset from earlier in the chapter from Excel and also from Google Sheets, with no additional arguments supplied to the read_excel() and read_sheet() functions. Are the resulting data frames in R exactly the same? If not, how are they different?

  2. Read the Google Sheet titled survey from https://pos.it/r4ds-survey, with survey_id as a character variable and n_pets as a numerical variable.

  3. Read the Google Sheet titled roster from https://pos.it/r4ds-roster. The resulting data frame should be called roster and should look like the following.

    #> # A tibble: 12 × 3
    #>    group subgroup    id
    #>    <dbl> <chr>    <dbl>
    #>  1     1 A            1
    #>  2     1 A            2
    #>  3     1 A            3
    #>  4     1 B            4
    #>  5     1 B            5
    #>  6     1 B            6
    #>  7     1 B            7
    #>  8     2 A            8
    #>  9     2 A            9
    #> 10     2 B           10
    #> 11     2 B           11
    #> 12     2 B           12

Summary

In this chapter you learned how to read data into R from spreadsheets: from Microsoft Excel with read_excel() from the readxl package and from Google Sheets with read_sheet() from the googlesheets4 package. These functions work very similarly to each other and have similar arguments for specifying column names, NA strings, rows to skip on top of the file you’re reading in, etc. Additionally, both functions make it possible to read a single sheet from a spreadsheet as well.

On the other hand, writing to an Excel file requires a different package and function (writexl::write_xlsx()) while you can write to a Google Sheet with the googlesheets4 package, with write_sheet().

In the next chapter, you’ll learn about a different data source and how to read data from that source into R: databases.