Chapter 8 - Data Import

Last updated: 2020-10-22

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options(scipen=10000)
library(tidyverse)
library(flair)
library(emo)
library(lubridate)
library(magrittr)

Inline csv file

read_csv("a,b,c
1,2,3
4,5,6")

# A tibble: 2 x 3
      a     b     c
  <dbl> <dbl> <dbl>
1     1     2     3
2     4     5     6

Skip some columns

metadata
commented lines that you don’t want to read

read_csv("The first line of metadata
  The second line of metadata
  x,y,z
  1,2,3", skip = 2)

# A tibble: 1 x 3
      x     y     z
  <dbl> <dbl> <dbl>
1     1     2     3

read_csv("# A comment I want to skip
  x,y,z
  1,2,3", comment = "#")

# A tibble: 1 x 3
      x     y     z
  <dbl> <dbl> <dbl>
1     1     2     3

No column names in data

read_csv("1,2,3\n4,5,6", 
         # \n adds a new line 
         col_names = FALSE
         # cols will be labelled seq from X1 .. Xn
         )

# A tibble: 2 x 3
     X1    X2    X3
  <dbl> <dbl> <dbl>
1     1     2     3
2     4     5     6

read_csv("1,2,3\n4,5,6", 
         # cols named as you provided here
         col_names = c("x", "y", "z"))

# A tibble: 2 x 3
      x     y     z
  <dbl> <dbl> <dbl>
1     1     2     3
2     4     5     6

NA values

read_csv("a,b,c,d\nnull,1,2,.", 
         # here we specify that the . and null
         # must be considered to be missing values
         na = c(".",
                "null"))

# A tibble: 1 x 4
  a         b     c d    
  <lgl> <dbl> <dbl> <lgl>
1 NA        1     2 NA

Exercises

What function would you use to read a file where fields were separated with
“|”?

read_delim()

# from the ?read_delim help page
read_delim("a|b\n1.0|2.0", delim = "|")

# A tibble: 1 x 2
      a     b
  <dbl> <dbl>
1     1     2

Apart from file, skip, and comment, what other arguments do read_csv() and read_tsv() have in common?

All columns are common across the functions.
- col_names
- col_types
- locale
- na
- quoted_na
- quote
- trim_ws
- n_max
- guess_max
- progress
- skip_empty_rows
What are the most important arguments to read_fwf()?
- file to read
- col_positions as created by fwf_empty(), fwf_widths() or fwf_positions() which tells the function where a column starts and ends.
Sometimes strings in a CSV file contain commas. To prevent them from causing problems they need to be surrounded by a quoting character, like " or '. By default, read_csv() assumes that the quoting character will be ". What argument to read_csv() do you need to specify to read the following text into a data frame?
```
"x,y\n1,'a,b'"
```
Specify the quote argument.
```
read_csv("x,y\n1,'a,b'", 
         quote = "'")
```
```
# A tibble: 1 x 2
      x y    
  <dbl> <chr>
1     1 a,b  
```

Identify what is wrong with each of the following inline CSV files. What happens when you run the code?

read_csv("a,b\n1,2,3\n4,5,6") 
read_csv("a,b,c\n1,2\n1,2,3,4")
read_csv("a,b\n\"1")
read_csv("a,b\n1,2\na,b")
read_csv("a;b\n1;3")

read_csv(“a,b\n1,2,3\n4,5,6”)
only 2 cols specified but 3 values provided

read_csv(“a,b,c\n1,2\n1,2,3,4”)
3 col names provided, but either too few, or too many column values provided

read_csv(“a,b\n"1”)
2 col names provided, but only one value provided.
closing " missing

read_csv(“a,b\n1,2\na,b”) Nothing syntactically a problem, but the rows are filled
with the column headings?

read_csv(“a;b\n1;3”) the read_csv2 which reads ; as delimiters should have been used

They all run, but most have warnings, and some are not imported as expected.

read_csv("a,b\n1,2,3\n4,5,6")

Warning: 2 parsing failures.
row col  expected    actual         file
  1  -- 2 columns 3 columns literal data
  2  -- 2 columns 3 columns literal data

# A tibble: 2 x 2
      a     b
  <dbl> <dbl>
1     1     2
2     4     5

read_csv("a,b,c\n1,2\n1,2,3,4")

Warning: 2 parsing failures.
row col  expected    actual         file
  1  -- 3 columns 2 columns literal data
  2  -- 3 columns 4 columns literal data

# A tibble: 2 x 3
      a     b     c
  <dbl> <dbl> <dbl>
1     1     2    NA
2     1     2     3

read_csv("a,b\n\"1")

Warning: 2 parsing failures.
row col                     expected    actual         file
  1  a  closing quote at end of file           literal data
  1  -- 2 columns                    1 columns literal data

# A tibble: 1 x 2
      a b    
  <dbl> <chr>
1     1 <NA>

read_csv("a,b\n1,2\na,b")

# A tibble: 2 x 2
  a     b    
  <chr> <chr>
1 1     2    
2 a     b

read_csv("a;b\n1;3")

# A tibble: 1 x 1
  `a;b`
  <chr>
1 1;3

Parsing

str(parse_logical(c("TRUE", "FALSE", "NA")))


 logi [1:3] TRUE FALSE NA

str(parse_integer(c("1", "2", "3")))


 int [1:3] 1 2 3

str(parse_date(c("2010-01-01", "1979-10-14")))


 Date[1:2], format: "2010-01-01" "1979-10-14"

All parse_xxx() variants provide a uniform specification to use.

parse_x(character_vector_to_parse, na = c(x, y))

parse_integer(c("1", "231", ".", "456"), na = ".")

[1]   1 231  NA 456

(x <- parse_integer(c("123", "345", "abc", "123.45")))

Warning: 2 parsing failures.
row col               expected actual
  3  -- an integer                abc
  4  -- no trailing characters    .45

[1] 123 345  NA  NA
attr(,"problems")
# A tibble: 2 x 4
    row   col expected               actual
  <int> <int> <chr>                  <chr> 
1     3    NA an integer             abc   
2     4    NA no trailing characters .45

To detect problems use problems().

problems(x)


# A tibble: 2 x 4
    row   col expected               actual
  <int> <int> <chr>                  <chr> 
1     3    NA an integer             abc   
2     4    NA no trailing characters .45

Sometimes depending on where in the world you are, you will have different conventions when it comes to numbers.

For example you may separate the integer part from the decimal part by using a . or a ,. To tell the parsing function what kind of data you’re expecting to be in a vector use locale = locale(...) in your parsing function.

parse_double("1.23")


[1] 1.23

parse_double("1,23", locale = locale(decimal_mark = ","))


[1] 1.23

parse_number("$100")

[1] 100

parse_number("20%")

[1] 20

parse_number("It cost $123.45")

[1] 123.45

# Used in America
parse_number("$123,456,789")

[1] 123456789

# Used in many parts of Europe
parse_number("123.456.789", 
             locale = locale(grouping_mark = "."))

[1] 123456789

# Used in Switzerland
parse_number("123'456'789", 
             locale = locale(grouping_mark = "'"))

[1] 123456789

charToRaw("Hadley")

[1] 48 61 64 6c 65 79

charToRaw("Vebash")

[1] 56 65 62 61 73 68

(x1 <- "El Ni\xf1o was particularly bad this year")

[1] "El Niño was particularly bad this year"

(x2 <- "\x82\xb1\x82\xf1\x82\xc9\x82\xbf\x82\xcd")

[1] "‚±‚ñ‚É‚¿‚Í"

To fix the problem you need to specify the encoding in parse_character():

parse_character(x1, 
                locale = locale(encoding = "Latin1"))


[1] "El Niño was particularly bad this year"

parse_character(x2, 
                locale = locale(encoding = "Shift-JIS"))


[1] "<U+3053><U+3093><U+306B><U+3061><U+306F>"

You can try the guess_encoding() to help you out:

guess_encoding(charToRaw(x1))

# A tibble: 2 x 2
  encoding   confidence
  <chr>           <dbl>
1 ISO-8859-1       0.46
2 ISO-8859-9       0.23

guess_encoding(charToRaw(x2))

# A tibble: 1 x 2
  encoding confidence
  <chr>         <dbl>
1 KOI8-R         0.42

fruit <- c("apple", "banana")
parse_factor(c("apple", "banana", "bananana"), 
             levels = fruit)

[1] apple  banana <NA>  
attr(,"problems")
# A tibble: 1 x 4
    row   col expected           actual  
  <int> <int> <chr>              <chr>   
1     3    NA value in level set bananana
Levels: apple banana

parse_datetime("2010-10-01T2010")

[1] "2010-10-01 20:10:00 UTC"

# If time is omitted, it will be set to midnight
parse_datetime("20101010")

[1] "2010-10-10 UTC"

parse_date("2010-10-01")

[1] "2010-10-01"

library(hms)
parse_time("01:10 am")

01:10:00

parse_time("20:10:01")

20:10:01

parse_date("01/02/15", "%m/%d/%y")

[1] "2015-01-02"

parse_date("01/02/15", "%d/%m/%y")

[1] "2015-02-01"

parse_date("01/02/15", "%y/%m/%d")

[1] "2001-02-15"

parse_date("1 janvier 2015", "%d %B %Y", 
           locale = locale("fr"))

[1] "2015-01-01"

Exercises

What are the most important arguments to locale()?
- The date_names, for example above we specified “fr” for French date names in order to parse the date.
- decimal_mark: Due to differences in locale, you should set this if your decimal numbers are separated using something other than ..
- grouping_mark: The default is “,” since that is what is used in the US, but if your grouping_mark is different, you should set this argument for your analysis.
- tz: The default tz is UTC, but you may want to change it to your timezone.

What happens if you try and set decimal_mark and grouping_mark to the same character? What happens to the default value of grouping_mark when you set decimal_mark to “,”? What happens to the default value of decimal_mark when you set the grouping_mark to “.”?

What happens if you try and set decimal_mark and grouping_mark to the same character?

# decimal_mark` and `grouping_mark` 
# to the same character
parse_double("123,456,78", 
             locale = locale(decimal_mark = ",",
                             grouping_mark = ","))
parse_number("123,456,78", 
             locale = locale(decimal_mark = ",",
                             grouping_mark = ","))

We get # Error: decimal_mark and grouping_mark must be different when using both parse_number and parse_double.

What happens to the default value of grouping_mark when you set decimal_mark to “,”?

parse_number("123 456,78", locale = 
               locale(decimal_mark = ","))

[1] 123

# when both are specified, 
# number parsed correctly
parse_number("123 456,78", locale = 
               locale(decimal_mark = ",",
                      grouping_mark = " "))

[1] 123456.8

# even though no grouping_mark specified, 
# parse_number handles the grouping mark 
# of . well.
# Below the reason is revealed to be the default
# switching in the readr code
parse_number("123.456,78", 
             locale = locale(decimal_mark = ","))

[1] 123456.8

# preserve the decimals
print(parse_number("123.456,78", 
        locale = locale(decimal_mark = ",")),
        digits=10)

[1] 123456.78

print(parse_number("123456789,11", 
        locale = locale(decimal_mark = ",")),
        digits=15)

[1] 123456789.11

In parse_number no grouping preserved, whitespace is not considered as group so we get an incorrect parsing. Initially I thought that since we overrode decimal_mark to be equal to the grouping_mark default, this removes the default, and hence has to be supplied for correct parsing if you also have a specific grouping character present.

Turns out the code sets the decimal_mark if it was not set, or vice versa, but it can’t be exhaustive and hence chooses to toggle between the . and ,.

Defaults are that decimal_mark = . and grouping_mark = ,. If you only change the decimal_mark
to be ,, and don’t specify any grouping mark it is defaulted to be .

But in this case we’ve got a grouping_mark that is a space, and have not specified that, hence the parsing does not occur well.

My take away here is even knowing that the code defaults the grouping_mark to be . if you set the decimal_mark to be , we should always be vigilant and override both to ensure parsing happens as expected.

From readr code file locale.R.

  if (missing(grouping_mark) && 
      !missing(decimal_mark)) {
    grouping_mark <- if (decimal_mark == ".") "," 
                     else "."
  } else if (missing(decimal_mark) && 
             !missing(grouping_mark)) {
    decimal_mark <- if (grouping_mark == ".") "," 
                    else "."
  }

For parse_double() we experience different results.

parse_double("123456,78", 
             locale = locale(decimal_mark = ","))

[1] 123456.8

parse_double("123.456,78", 
             locale = locale(decimal_mark = ","))

[1] NA
attr(,"problems")
# A tibble: 1 x 4
    row   col expected               actual 
  <int> <int> <chr>                  <chr>  
1     1    NA no trailing characters .456,78

parse_double("123.456,78", 
             locale = locale(decimal_mark = ",",
                             grouping_mark = "."))

[1] NA
attr(,"problems")
# A tibble: 1 x 4
    row   col expected               actual 
  <int> <int> <chr>                  <chr>  
1     1    NA no trailing characters .456,78

parse_double("123 456,78", 
             locale = locale(decimal_mark = ",",
                             grouping_mark = " "))

[1] NA
attr(,"problems")
# A tibble: 1 x 4
    row   col expected               actual   
  <int> <int> <chr>                  <chr>    
1     1    NA no trailing characters " 456,78"

Hhmm okay, so it seems like parse_double() is a bit more strict, and does not seem to like it even if we override the locale(). This Stack Overflow post confirms what we see here, so too does this post and this one. The only perplexing thing is that when I do set the grouping_mark in locale() why is this not considered? Because parse_double() also has a default locale which may be overriden by locale()? 😕

What happens to the default value of decimal_mark when you set the grouping_mark to “.”?

# As above shows the decimal character 
# set to , in code
parse_number("5.123.456,78", 
             locale = locale(grouping_mark = "."))

[1] 5123457

parse_number("5.123.456,78", 
             locale = locale(decimal_mark = ",",
                             grouping_mark = "."))

[1] 5123457

problems(parse_double("5.123.456,78", 
                      locale = locale(
                        decimal_mark = ",",
                        grouping_mark = ".")))

# A tibble: 1 x 4
    row   col expected               actual     
  <int> <int> <chr>                  <chr>      
1     1    NA no trailing characters .123.456,78

I didn’t discuss the date_format and time_format options to locale(). What do they do? Construct an example that shows when they might be useful.

Dates and times may be specified in numerous ways. Dates for example can be YYYY-MM-DD or MM-DD-YY.

Times are the same. It may be hh:mm:ss or hh:mm AM/PM.

It may be useful to use this if you know your data contains dates / times in a different for from the default.

locale("zu")

<locale>
Numbers:  123,456.78
Formats:  %AD / %AT
Timezone: UTC
Encoding: UTF-8
<date_names>
Days:   Sonto (Son), Msombuluko (Mso), Lwesibili (Bil), Lwesithathu (Tha),
        Lwesine (Sin), Lwesihlanu (Hla), Mgqibelo (Mgq)
Months: Januwari (Jan), Februwari (Feb), Mashi (Mas), Apreli (Apr), Meyi (Mey),
        Juni (Jun), Julayi (Jul), Agasti (Aga), Septhemba (Sep),
        Okthoba (Okt), Novemba (Nov), Disemba (Dis)
AM/PM:  Ekuseni/Ntambama

locale("af")

<locale>
Numbers:  123,456.78
Formats:  %AD / %AT
Timezone: UTC
Encoding: UTF-8
<date_names>
Days:   Sondag (So), Maandag (Ma), Dinsdag (Di), Woensdag (Wo), Donderdag (Do),
        Vrydag (Vr), Saterdag (Sa)
Months: Januarie (Jan.), Februarie (Feb.), Maart (Mrt.), April (Apr), Mei
        (Mei), Junie (Jun), Julie (Jul), Augustus (Aug), September
        (Sep), Oktober (Okt), November (Nov), Desember (Des)
AM/PM:  vm./nm.

locale_af <- locale("af", date_format = "%m %d",
       time_format = "%H:%M")

read_csv("a, date, time
         x, Mrt. 23, 20:30
         y, Okt. 31, 15:45", locale = locale_af)

# A tibble: 2 x 3
  a     date    time  
  <chr> <chr>   <time>
1 x     Mrt. 23 20:30 
2 y     Okt. 31 15:45

If you live outside the US, create a new locale object that encapsulates the settings for the types of file you read most commonly.
```
locale_za = locale("en", date_format = "%Y-%m-%d",
                   time_format = "%H:%M:%S")
```
What’s the difference between read_csv() and read_csv2()?
- read_csv2() has ; as a delimiter.
- read_csv() has , as a delimiter.
What are the most common encodings used in Europe? What are the most common encodings used in Asia? Do some googling to find out.

UTF-8 is the standard it seems. Other than this:
- Europe seems to be Latin-1.
- Asia seems to be Shift-JIS

Generate the correct format string to parse each of the following dates and times:

d1 <- "January 1, 2010"
d2 <- "2015-Mar-07"
d3 <- "06-Jun-2017"
d4 <- c("August 19 (2015)", "July 1 (2015)")
d5 <- "12/30/14" # Dec 30, 2014
t1 <- "1705"
t2 <- "11:15:10.12 PM"

d1 <- "January 1, 2010"
parse_date(d1, "%B %d, %Y")

[1] "2010-01-01"

d2 <- "2015-Mar-07"
parse_date(d2, "%Y-%b-%d")

[1] "2015-03-07"

d3 <- "06-Jun-2017"
parse_date(d3, "%d-%b-%Y")

[1] "2017-06-06"

d4 <- c("August 19 (2015)", "July 1 (2015)")
parse_date(d4, "%B %d (%Y)")

[1] "2015-08-19" "2015-07-01"

d5 <- "12/30/14" # Dec 30, 2014
parse_date(d5, "%m/%d/%y")

[1] "2014-12-30"

t1 <- "1705"
parse_time(t1, "%H%M")

17:05:00

t2 <- "11:15:10.12 PM"
parse_time(t2, "%I:%M:%OS %p")

23:15:10.12

readr Strategy

The readr 📦 uses the first 1000 entries in a column to guess the type of data contained in that column. This may work okay for most cases, but if you have sorted a file in a certain way (e.g. all missing values up top) then you may end up with a column inference that doesn’t quite work.

guess_parser("2010-10-01")

[1] "date"

guess_parser("15:01")

[1] "time"

guess_parser(c("TRUE", "FALSE"))

[1] "logical"

guess_parser(c("1", "5", "9"))

[1] "double"

guess_parser(c("12,352,561"))

[1] "number"

str(parse_guess("2010-10-10"))

 Date[1:1], format: "2010-10-10"

challenge <- read_csv(readr_example("challenge.csv"))

problems(challenge)

# A tibble: 1,000 x 5
     row col   expected       actual   file                                     
   <int> <chr> <chr>          <chr>    <chr>                                    
 1  1001 y     1/0/T/F/TRUE/~ 2015-01~ 'C:/Users/vebashini/Documents/R/win-libr~
 2  1002 y     1/0/T/F/TRUE/~ 2018-05~ 'C:/Users/vebashini/Documents/R/win-libr~
 3  1003 y     1/0/T/F/TRUE/~ 2015-09~ 'C:/Users/vebashini/Documents/R/win-libr~
 4  1004 y     1/0/T/F/TRUE/~ 2012-11~ 'C:/Users/vebashini/Documents/R/win-libr~
 5  1005 y     1/0/T/F/TRUE/~ 2020-01~ 'C:/Users/vebashini/Documents/R/win-libr~
 6  1006 y     1/0/T/F/TRUE/~ 2016-04~ 'C:/Users/vebashini/Documents/R/win-libr~
 7  1007 y     1/0/T/F/TRUE/~ 2011-05~ 'C:/Users/vebashini/Documents/R/win-libr~
 8  1008 y     1/0/T/F/TRUE/~ 2020-07~ 'C:/Users/vebashini/Documents/R/win-libr~
 9  1009 y     1/0/T/F/TRUE/~ 2011-04~ 'C:/Users/vebashini/Documents/R/win-libr~
10  1010 y     1/0/T/F/TRUE/~ 2010-05~ 'C:/Users/vebashini/Documents/R/win-libr~
# ... with 990 more rows

tail(challenge)

# A tibble: 6 x 2
      x y    
  <dbl> <lgl>
1 0.805 NA   
2 0.164 NA   
3 0.472 NA   
4 0.718 NA   
5 0.270 NA   
6 0.608 NA

When you encounter problems:

Work column by column to fix.
Copy and paste the specification that read_xxx() inferred and use it to adjust the columns you experienced issues on. Just a note here: in the old version of readr the x column had integers up front, and hence was inferred as integer. Now it is inferred as double so the file only has an issue with the second column that has many NA values up top, and hence is considered incorrectly to be a logical when it is in fact a date.

I am a little perplexed by this though because the first 1000 rows are only integers. I would guess that the heuristic has been amended and maybe integer has been removed?

challenge <- read_csv(
  readr_example("challenge.csv"), 
  col_types = cols(
    x = col_double(),
    # change here from col_logical() to
    # col_date()
    y = col_date() 
  )
)
tail(challenge)

# A tibble: 6 x 2
      x y         
  <dbl> <date>    
1 0.805 2019-11-21
2 0.164 2018-03-29
3 0.472 2014-08-04
4 0.718 2015-08-16
5 0.270 2020-02-04
6 0.608 2019-01-06

challenge %>% 
  head(1010) %>% 
  tail(11)

# A tibble: 11 x 2
          x y         
      <dbl> <date>    
 1 4548     NA        
 2    0.238 2015-01-16
 3    0.412 2018-05-18
 4    0.746 2015-09-05
 5    0.723 2012-11-28
 6    0.615 2020-01-13
 7    0.474 2016-04-17
 8    0.578 2011-05-14
 9    0.242 2020-07-18
10    0.114 2011-04-30
11    0.298 2010-05-11

challenge %>% 
  head(1000) %>% 
  filter(as.integer(x) != x)

# A tibble: 0 x 2
# ... with 2 variables: x <dbl>, y <date>

challenge %>% 
  head(1000) %>% 
  filter(x%%1!=0)

# A tibble: 0 x 2
# ... with 2 variables: x <dbl>, y <date>

challenge %>% 
  tail(1000) %>% 
  filter(as.integer(x) != x)

# A tibble: 1,000 x 2
       x y         
   <dbl> <date>    
 1 0.238 2015-01-16
 2 0.412 2018-05-18
 3 0.746 2015-09-05
 4 0.723 2012-11-28
 5 0.615 2020-01-13
 6 0.474 2016-04-17
 7 0.578 2011-05-14
 8 0.242 2020-07-18
 9 0.114 2011-04-30
10 0.298 2010-05-11
# ... with 990 more rows

(test_file <- read_csv("a, b, c
# Trying to confirm if integers get read in a double?
                      1, 2.3, 'x'
                      2, 5.4, 'y'
                      3, 6.7, 'z'"))

# A tibble: 4 x 3
  a                                                         b c    
  <chr>                                                 <dbl> <chr>
1 # Trying to confirm if integers get read in a double?  NA   <NA> 
2 1                                                       2.3 'x'  
3 2                                                       5.4 'y'  
4 3                                                       6.7 'z'

Writing files

write_csv(dataset, “file path”)
write_tsv(dataset, “file_path”)
write_excel_csv(dataset, “file_path”). I did not know about this one! 🙏

The only issue with the above is you need to recreate the specification on every subsequent read.

write_rds() [to read use read_rds()] stores data in R’s custom binary format called RDS.
write_feather() [and read_feather()] from the feather 📦 allows files to be shared across languages.

sessionInfo()

R version 3.6.3 (2020-02-29)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18363)

Matrix products: default

locale:
[1] LC_COLLATE=English_South Africa.1252  LC_CTYPE=English_South Africa.1252   
[3] LC_MONETARY=English_South Africa.1252 LC_NUMERIC=C                         
[5] LC_TIME=English_South Africa.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] hms_0.5.3       magrittr_1.5    lubridate_1.7.8 emo_0.0.0.9000 
 [5] flair_0.0.2     forcats_0.5.0   stringr_1.4.0   dplyr_1.0.0    
 [9] purrr_0.3.4     readr_1.3.1     tidyr_1.1.0     tibble_3.0.3   
[13] ggplot2_3.3.0   tidyverse_1.3.0 workflowr_1.6.2

loaded via a namespace (and not attached):
 [1] tidyselect_1.1.0 xfun_0.13        haven_2.2.0      lattice_0.20-38 
 [5] colorspace_1.4-1 vctrs_0.3.2      generics_0.0.2   htmltools_0.5.0 
 [9] yaml_2.2.1       utf8_1.1.4       rlang_0.4.7      later_1.0.0     
[13] pillar_1.4.6     withr_2.2.0      glue_1.4.1       DBI_1.1.0       
[17] dbplyr_1.4.3     modelr_0.1.6     readxl_1.3.1     lifecycle_0.2.0 
[21] munsell_0.5.0    gtable_0.3.0     cellranger_1.1.0 rvest_0.3.5     
[25] evaluate_0.14    knitr_1.28       httpuv_1.5.2     fansi_0.4.1     
[29] broom_0.5.6      Rcpp_1.0.4.6     promises_1.1.0   backports_1.1.6 
[33] scales_1.1.0     jsonlite_1.7.0   fs_1.4.1         digest_0.6.25   
[37] stringi_1.4.6    grid_3.6.3       rprojroot_1.3-2  cli_2.0.2       
[41] tools_3.6.3      crayon_1.3.4     whisker_0.4      pkgconfig_2.0.3 
[45] ellipsis_0.3.1   xml2_1.3.2       reprex_0.3.0     rstudioapi_0.11 
[49] assertthat_0.2.1 rmarkdown_2.4    httr_1.4.2       R6_2.4.1        
[53] nlme_3.1-144     git2r_0.26.1     compiler_3.6.3

Chapter 8 - Data Import

Vebash Naidoo

18/10/2020

Exercises

Parsing

Exercises

readr Strategy

Other strategies for read issues

Writing files