Import data with readr

readr 패키지로 데이터를 R로 가져오는 방법을 숙지합니다.

들어가기

대용량 데이터는 이제부터 readr을 사용하자. 왜? 속도가 빠르기 때문에 필요없는 대기 시간을 줄여주기 때문입니다.
readr은 파일의 인코딩을 유추할 수 있는 기능이 있어 특히 한글 파일을 import할 때 유용합니다.

준비하기

데이터 파일 준비하기

다음과 같은 데이터 파일을 다운로드 한다. 브라우저의 다른 이름으로 링크 저장 기능을 이용해서 파일을 다운로드 합니다.

• 아파트매매_실거래가_200001.csv
  • 한글이 포함된 데이터 파일
  • CSV 파일(컴마를 구분자로 한 텍스트 파일)
  • 한글이 “cp949”로 인코딩되어 있음
• FoodFacts.tsv
  • 대용량 데이터 파일
  • TSV 파일(탭문자를 구분자로 한 텍스트 파일)

“data” 라는 디렉토리를 생성하고, 다운로드한 데이터 파일을 복사해 넣습는다.

실습하기

CSV 파일 읽기

기존 방법

read.csv() 함수는 CSV 파일을 읽을 수 있는 함수입니다.

apt <- read.csv(file = "data/아파트매매_실거래가_200001.csv", 
                header = TRUE, 
                fileEncoding = "cp949",
                stringsAsFactors = FALSE)

str(apt)

'data.frame':   58805 obs. of  13 variables:
 $ 시군구        : chr  "강원도 강릉시 견소동" "강원도 강릉시 견소동" "강원도 강릉시 견소동" "강원도 강릉시 견소동" ...
 $ 번지          : chr  "202" "202" "202" "202" ...
 $ 본번          : chr  "0202" "0202" "0202" "0202" ...
 $ 부번          : chr  "0000" "0000" "0000" "0000" ...
 $ 단지명        : chr  "송정한신" "송정한신" "송정한신" "송정한신" ...
 $ 전용면적...   : num  43.4 59.8 59.8 84.9 116.2 ...
 $ 계약년월      : int  202001 202001 202001 202001 202001 202001 202001 202001 202001 202001 ...
 $ 계약일        : int  3 15 18 18 21 23 6 20 27 4 ...
 $ 거래금액.만원.: chr  "12,000" "10,000" "10,500" "13,500" ...
 $ 층            : int  12 3 12 11 5 8 10 15 8 14 ...
 $ 건축년도      : int  1997 1997 1997 1997 1997 1997 2005 2009 2009 1999 ...
 $ 도로명        : chr  "경강로2539번길 8" "경강로2539번길 8" "경강로2539번길 8" "경강로2539번길 8" ...
 $ 해제사유발생일: logi  NA NA NA NA NA NA ...

dim(apt)

[1] 58805    13

readr

read_csv() 함수는 readr 패키지에서 CSV 파일을 읽을 수 있는 함수입니다.

그런데 read_csv() 함수로 영문 파일이 아닌 멀티 바이트 문자 파일을 읽을 때 에러가 발생 할 수 있습니다. 이 경우는 guess_encoding() 함수로 파일의 인코딩을 유추할 수 있습니다. 그러나 read.csv()에서의 사용하는 인코딩 이름과 체계가 다를 수 있습니다. “cp949”가 “EUC-KR”로 유추됩니다. read_csv() 함수에 “EUC-KR” 인코딩 이름을 적용해도 결과는 동일합니다.

library(readr)
library(dplyr)

apt2 <- read_csv(file = "data/아파트매매_실거래가_200001.csv",
                 locale = locale(encoding = "cp949"))

str(apt2)

spec_tbl_df [58,805 × 13] (S3: spec_tbl_df/tbl_df/tbl/data.frame)
 $ 시군구        : chr [1:58805] "강원도 강릉시 견소동" "강원도 강릉시 견소동" "강원도 강릉시 견소동" "강원도 강릉시 견소동" ...
 $ 번지          : chr [1:58805] "202" "202" "202" "202" ...
 $ 본번          : chr [1:58805] "0202" "0202" "0202" "0202" ...
 $ 부번          : chr [1:58805] "0000" "0000" "0000" "0000" ...
 $ 단지명        : chr [1:58805] "송정한신" "송정한신" "송정한신" "송정한신" ...
 $ 전용면적(㎡)  : num [1:58805] 43.4 59.8 59.8 84.9 116.2 ...
 $ 계약년월      : num [1:58805] 202001 202001 202001 202001 202001 ...
 $ 계약일        : num [1:58805] 3 15 18 18 21 23 6 20 27 4 ...
 $ 거래금액(만원): num [1:58805] 12000 10000 10500 13500 19000 ...
 $ 층            : num [1:58805] 12 3 12 11 5 8 10 15 8 14 ...
 $ 건축년도      : num [1:58805] 1997 1997 1997 1997 1997 ...
 $ 도로명        : chr [1:58805] "경강로2539번길 8" "경강로2539번길 8" "경강로2539번길 8" "경강로2539번길 8" ...
 $ 해제사유발생일: logi [1:58805] NA NA NA NA NA NA ...
 - attr(*, "spec")=
  .. cols(
  ..   시군구 = col_character(),
  ..   번지 = col_character(),
  ..   본번 = col_character(),
  ..   부번 = col_character(),
  ..   단지명 = col_character(),
  ..   `전용면적(㎡)` = col_double(),
  ..   계약년월 = col_double(),
  ..   계약일 = col_double(),
  ..   `거래금액(만원)` = col_number(),
  ..   층 = col_double(),
  ..   건축년도 = col_double(),
  ..   도로명 = col_character(),
  ..   해제사유발생일 = col_logical()
  .. )
 - attr(*, "problems")=<externalptr> 

dim(apt2)

[1] 58805    13

# 파일의 10줄을 읽어서 인코딩을 유추합니다.
read_lines("data/아파트매매_실거래가_200001.csv", n_max = 10) %>% 
  guess_encoding()

# A tibble: 3 x 2
  encoding confidence
  <chr>         <dbl>
1 EUC-KR         1   
2 GB18030        0.58
3 Big5           0.34

read.csv() 함수는 data.frame 객체를 반환하지만, read 패키지의 함수들은 tibble 객체를 반환합니다.

대용량 TSV 파일 읽기

FoodFacts.tsv 파일은 약 92MB의 용량으로 대용량이라 보기 어렵지만, 실습 차원에서 대용량으로 간주하여 진행합니다.

file.size("data/FoodFacts.tsv") / 1024^2

[1] 91.65345

기존 방법

read.csv() 함수는 TSV 파일을 읽을 수 있는 함수입니다.

elapse_old <- system.time(
  foodfact <- read.csv(file = "data/FoodFacts.tsv",
                       sep = "\t",
                       header = TRUE, 
                       stringsAsFactors = FALSE)
)

elapse_old

   user  system elapsed 
  2.568   0.086   2.663 

dim(foodfact)

[1] 23179   163

str(foodfact)

'data.frame':   23179 obs. of  163 variables:
 $ code                                      : num  3087 4530 4559 16087 16094 ...
 $ url                                       : chr  "http://world-en.openfoodfacts.org/product/0000000003087/farine-de-ble-noir-ferme-t-y-r-nao" "http://world-en.openfoodfacts.org/product/0000000004530/banana-chips-sweetened-whole" "http://world-en.openfoodfacts.org/product/0000000004559/peanuts-torn-glasser" "http://world-en.openfoodfacts.org/product/0000000016087/organic-salted-nut-mix-grizzlies" ...
 $ creator                                   : chr  "openfoodfacts-contributors" "usda-ndb-import" "usda-ndb-import" "usda-ndb-import" ...
 $ created_t                                 : int  1474103866 1489069957 1489069957 1489055731 1489055653 1489055651 1489055730 1489055711 1489055651 1489055654 ...
 $ created_datetime                          : chr  "2016-09-17T09:17:46Z" "2017-03-09T14:32:37Z" "2017-03-09T14:32:37Z" "2017-03-09T10:35:31Z" ...
 $ last_modified_t                           : int  1474103893 1489069957 1489069957 1489055731 1489055653 1489055651 1489055730 1489055712 1489055651 1489055654 ...
 $ last_modified_datetime                    : chr  "2016-09-17T09:18:13Z" "2017-03-09T14:32:37Z" "2017-03-09T14:32:37Z" "2017-03-09T10:35:31Z" ...
 $ product_name                              : chr  "Farine de blé noir" "Banana Chips Sweetened (Whole)" "Peanuts" "Organic Salted Nut Mix" ...
 $ generic_name                              : chr  "" "" "" "" ...
 $ quantity                                  : chr  "1kg" "" "" "" ...
 $ packaging                                 : chr  "" "" "" "" ...
 $ packaging_tags                            : chr  "" "" "" "" ...
 $ brands                                    : chr  "Ferme t'y R'nao" "" "Torn & Glasser" "Grizzlies" ...
 $ brands_tags                               : chr  "ferme-t-y-r-nao" "" "torn-glasser" "grizzlies" ...
 $ categories                                : chr  "" "" "" "" ...
 $ categories_tags                           : chr  "" "" "" "" ...
 $ categories_en                             : chr  "" "" "" "" ...
 $ origins                                   : chr  "" "" "" "" ...
 $ origins_tags                              : chr  "" "" "" "" ...
 $ manufacturing_places                      : chr  "" "" "" "" ...
 $ manufacturing_places_tags                 : chr  "" "" "" "" ...
 $ labels                                    : chr  "" "" "" "" ...
 $ labels_tags                               : chr  "" "" "" "" ...
 $ labels_en                                 : chr  "" "" "" "" ...
 $ emb_codes                                 : chr  "" "" "" "" ...
 $ emb_codes_tags                            : chr  "" "" "" "" ...
 $ first_packaging_code_geo                  : chr  "" "" "" "" ...
 $ cities                                    : logi  NA NA NA NA NA NA ...
 $ cities_tags                               : chr  "" "" "" "" ...
 $ purchase_places                           : chr  "" "" "" "" ...
 $ stores                                    : chr  "" "" "" "" ...
 $ countries                                 : chr  "en:FR" "US" "US" "US" ...
 $ countries_tags                            : chr  "en:france" "en:united-states" "en:united-states" "en:united-states" ...
 $ countries_en                              : chr  "France" "United States" "United States" "United States" ...
 $ ingredients_text                          : chr  "" "Bananas, vegetable oil (coconut oil, corn oil and/or palm oil) sugar, natural banana flavor." "Peanuts, wheat flour, sugar, rice flour, tapioca starch, salt, leavening (ammonium bicarbonate, baking soda), s"| __truncated__ "Organic hazelnuts, organic cashews, organic walnuts almonds, organic sunflower oil, sea salt." ...
 $ allergens                                 : chr  "" "" "" "" ...
 $ allergens_en                              : logi  NA NA NA NA NA NA ...
 $ traces                                    : chr  "" "" "" "" ...
 $ traces_tags                               : chr  "" "" "" "" ...
 $ traces_en                                 : chr  "" "" "" "" ...
 $ serving_size                              : chr  "" "28 g (1 ONZ)" "28 g (0.25 cup)" "28 g (0.25 cup)" ...
 $ no_nutriments                             : logi  NA NA NA NA NA NA ...
 $ additives_n                               : int  NA 0 0 0 0 0 0 1 0 0 ...
 $ additives                                 : chr  "" " [ bananas -> en:bananas  ]  [ vegetable-oil -> en:vegetable-oil  ]  [ oil -> en:oil  ]  [ coconut-oil -> en:co"| __truncated__ " [ peanuts -> en:peanuts  ]  [ wheat-flour -> en:wheat-flour  ]  [ flour -> en:flour  ]  [ sugar -> en:sugar  ]"| __truncated__ " [ organic-hazelnuts -> en:organic-hazelnuts  ]  [ hazelnuts -> en:hazelnuts  ]  [ organic-cashews -> en:organi"| __truncated__ ...
 $ additives_tags                            : chr  "" "" "" "" ...
 $ additives_en                              : chr  "" "" "" "" ...
 $ ingredients_from_palm_oil_n               : chr  "" "0" "0" "0" ...
 $ ingredients_from_palm_oil                 : logi  NA NA NA NA NA NA ...
 $ ingredients_from_palm_oil_tags            : chr  "" "" "" "" ...
 $ ingredients_that_may_be_from_palm_oil_n   : chr  "" "0" "0" "0" ...
 $ ingredients_that_may_be_from_palm_oil     : chr  "" "" "" "" ...
 $ ingredients_that_may_be_from_palm_oil_tags: chr  "" "" "" "" ...
 $ nutrition_grade_uk                        : int  NA NA NA NA NA NA NA NA NA NA ...
 $ nutrition_grade_fr                        : chr  "" "d" "b" "d" ...
 $ pnns_groups_1                             : chr  "" "" "" "" ...
 $ pnns_groups_2                             : chr  "" "" "" "" ...
 $ states                                    : chr  "en:to-be-completed, en:nutrition-facts-to-be-completed, en:ingredients-to-be-completed, en:expiration-date-to-b"| __truncated__ "en:to-be-completed, en:nutrition-facts-completed, en:ingredients-completed, en:expiration-date-to-be-completed,"| __truncated__ "en:to-be-completed, en:nutrition-facts-completed, en:ingredients-completed, en:expiration-date-to-be-completed,"| __truncated__ "en:to-be-completed, en:nutrition-facts-completed, en:ingredients-completed, en:expiration-date-to-be-completed,"| __truncated__ ...
 $ states_tags                               : chr  "en:to-be-completed,en:nutrition-facts-to-be-completed,en:ingredients-to-be-completed,en:expiration-date-to-be-c"| __truncated__ "en:to-be-completed,en:nutrition-facts-completed,en:ingredients-completed,en:expiration-date-to-be-completed,en:"| __truncated__ "en:to-be-completed,en:nutrition-facts-completed,en:ingredients-completed,en:expiration-date-to-be-completed,en:"| __truncated__ "en:to-be-completed,en:nutrition-facts-completed,en:ingredients-completed,en:expiration-date-to-be-completed,en:"| __truncated__ ...
 $ states_en                                 : chr  "To be completed,Nutrition facts to be completed,Ingredients to be completed,Expiration date to be completed,Cha"| __truncated__ "To be completed,Nutrition facts completed,Ingredients completed,Expiration date to be completed,Packaging-code-"| __truncated__ "To be completed,Nutrition facts completed,Ingredients completed,Expiration date to be completed,Packaging-code-"| __truncated__ "To be completed,Nutrition facts completed,Ingredients completed,Expiration date to be completed,Packaging-code-"| __truncated__ ...
 $ main_category                             : chr  "" "" "" "" ...
 $ main_category_en                          : chr  "" "" "" "" ...
 $ image_url                                 : chr  "" "" "" "" ...
 $ image_small_url                           : chr  "" "" "" "" ...
 $ energy_100g                               : chr  "" "2243" "1941" "2540" ...
 $ energy.from.fat_100g                      : chr  "" "" "" "" ...
 $ fat_100g                                  : chr  "" "28.57" "17.86" "57.14" ...
 $ saturated.fat_100g                        : chr  "" "28.57" "0" "5.36" ...
 $ X.butyric.acid_100g                       : chr  "" "" "" "" ...
 $ X.caproic.acid_100g                       : num  NA NA NA NA NA NA NA NA NA NA ...
 $ X.caprylic.acid_100g                      : num  NA NA NA NA NA NA NA NA NA NA ...
 $ X.capric.acid_100g                        : logi  NA NA NA NA NA NA ...
 $ X.lauric.acid_100g                        : num  NA NA NA NA NA NA NA NA NA NA ...
 $ X.myristic.acid_100g                      : num  NA NA NA NA NA NA NA NA NA NA ...
 $ X.palmitic.acid_100g                      : chr  "" "" "" "" ...
 $ X.stearic.acid_100g                       : logi  NA NA NA NA NA NA ...
 $ X.arachidic.acid_100g                     : int  NA NA NA NA NA NA NA NA NA NA ...
 $ X.behenic.acid_100g                       : chr  "" "" "" "" ...
 $ X.lignoceric.acid_100g                    : chr  "" "" "" "" ...
 $ X.cerotic.acid_100g                       : chr  "" "" "" "" ...
 $ X.montanic.acid_100g                      : num  NA NA NA NA NA NA NA NA NA NA ...
 $ X.melissic.acid_100g                      : logi  NA NA NA NA NA NA ...
 $ monounsaturated.fat_100g                  : num  NA NA NA NA NA NA NA NA NA NA ...
 $ polyunsaturated.fat_100g                  : num  NA NA NA NA NA NA NA NA NA NA ...
 $ omega.3.fat_100g                          : num  NA NA NA NA NA NA NA NA NA NA ...
 $ X.alpha.linolenic.acid_100g               : num  NA NA NA NA NA NA NA NA NA NA ...
 $ X.eicosapentaenoic.acid_100g              : logi  NA NA NA NA NA NA ...
 $ X.docosahexaenoic.acid_100g               : chr  "" "" "" "" ...
 $ omega.6.fat_100g                          : logi  NA NA NA NA NA NA ...
 $ X.linoleic.acid_100g                      : logi  NA NA NA NA NA NA ...
 $ X.arachidonic.acid_100g                   : chr  "" "" "" "" ...
 $ X.gamma.linolenic.acid_100g               : chr  "" "" "" "" ...
 $ X.dihomo.gamma.linolenic.acid_100g        : chr  "" "" "" "" ...
 $ omega.9.fat_100g                          : logi  NA NA NA NA NA NA ...
 $ X.oleic.acid_100g                         : logi  NA NA NA NA NA NA ...
 $ X.elaidic.acid_100g                       : logi  NA NA NA NA NA NA ...
 $ X.gondoic.acid_100g                       : logi  NA NA NA NA NA NA ...
 $ X.mead.acid_100g                          : int  NA NA NA NA NA NA NA NA NA NA ...
 $ X.erucic.acid_100g                        : logi  NA NA NA NA NA NA ...
 $ X.nervonic.acid_100g                      : int  NA NA NA NA NA NA NA NA NA NA ...
  [list output truncated]

readr

read_tsv() 함수는 readr 패키지에서 TSV 파일을 읽을 수 있는 함수입니다.

elapse_readr <- system.time(
  foodfact2 <- read_tsv(file = "data/FoodFacts.tsv")
)

elapse_readr

   user  system elapsed 
  4.846   0.267   4.186 

dim(foodfact2)

[1] 35000   163

str(foodfact2)

spec_tbl_df [35,000 × 163] (S3: spec_tbl_df/tbl_df/tbl/data.frame)
 $ code                                      : chr [1:35000] "0000000003087" "0000000004530" "0000000004559" "0000000016087" ...
 $ url                                       : chr [1:35000] "http://world-en.openfoodfacts.org/product/0000000003087/farine-de-ble-noir-ferme-t-y-r-nao" "http://world-en.openfoodfacts.org/product/0000000004530/banana-chips-sweetened-whole" "http://world-en.openfoodfacts.org/product/0000000004559/peanuts-torn-glasser" "http://world-en.openfoodfacts.org/product/0000000016087/organic-salted-nut-mix-grizzlies" ...
 $ creator                                   : chr [1:35000] "openfoodfacts-contributors" "usda-ndb-import" "usda-ndb-import" "usda-ndb-import" ...
 $ created_t                                 : num [1:35000] 1.47e+09 1.49e+09 1.49e+09 1.49e+09 1.49e+09 ...
 $ created_datetime                          : POSIXct[1:35000], format: "2016-09-17 09:17:46" ...
 $ last_modified_t                           : num [1:35000] 1.47e+09 1.49e+09 1.49e+09 1.49e+09 1.49e+09 ...
 $ last_modified_datetime                    : POSIXct[1:35000], format: "2016-09-17 09:18:13" ...
 $ product_name                              : chr [1:35000] "Farine de blé noir" "Banana Chips Sweetened (Whole)" "Peanuts" "Organic Salted Nut Mix" ...
 $ generic_name                              : chr [1:35000] NA NA NA NA ...
 $ quantity                                  : chr [1:35000] "1kg" NA NA NA ...
 $ packaging                                 : chr [1:35000] NA NA NA NA ...
 $ packaging_tags                            : chr [1:35000] NA NA NA NA ...
 $ brands                                    : chr [1:35000] "Ferme t'y R'nao" NA "Torn & Glasser" "Grizzlies" ...
 $ brands_tags                               : chr [1:35000] "ferme-t-y-r-nao" NA "torn-glasser" "grizzlies" ...
 $ categories                                : chr [1:35000] NA NA NA NA ...
 $ categories_tags                           : chr [1:35000] NA NA NA NA ...
 $ categories_en                             : chr [1:35000] NA NA NA NA ...
 $ origins                                   : chr [1:35000] NA NA NA NA ...
 $ origins_tags                              : chr [1:35000] NA NA NA NA ...
 $ manufacturing_places                      : chr [1:35000] NA NA NA NA ...
 $ manufacturing_places_tags                 : chr [1:35000] NA NA NA NA ...
 $ labels                                    : chr [1:35000] NA NA NA NA ...
 $ labels_tags                               : chr [1:35000] NA NA NA NA ...
 $ labels_en                                 : chr [1:35000] NA NA NA NA ...
 $ emb_codes                                 : chr [1:35000] NA NA NA NA ...
 $ emb_codes_tags                            : chr [1:35000] NA NA NA NA ...
 $ first_packaging_code_geo                  : logi [1:35000] NA NA NA NA NA NA ...
 $ cities                                    : logi [1:35000] NA NA NA NA NA NA ...
 $ cities_tags                               : logi [1:35000] NA NA NA NA NA NA ...
 $ purchase_places                           : chr [1:35000] NA NA NA NA ...
 $ stores                                    : chr [1:35000] NA NA NA NA ...
 $ countries                                 : chr [1:35000] "en:FR" "US" "US" "US" ...
 $ countries_tags                            : chr [1:35000] "en:france" "en:united-states" "en:united-states" "en:united-states" ...
 $ countries_en                              : chr [1:35000] "France" "United States" "United States" "United States" ...
 $ ingredients_text                          : chr [1:35000] NA "Bananas, vegetable oil (coconut oil, corn oil and/or palm oil) sugar, natural banana flavor." "Peanuts, wheat flour, sugar, rice flour, tapioca starch, salt, leavening (ammonium bicarbonate, baking soda), s"| __truncated__ "Organic hazelnuts, organic cashews, organic walnuts almonds, organic sunflower oil, sea salt." ...
 $ allergens                                 : chr [1:35000] NA NA NA NA ...
 $ allergens_en                              : logi [1:35000] NA NA NA NA NA NA ...
 $ traces                                    : chr [1:35000] NA NA NA NA ...
 $ traces_tags                               : chr [1:35000] NA NA NA NA ...
 $ traces_en                                 : chr [1:35000] NA NA NA NA ...
 $ serving_size                              : chr [1:35000] NA "28 g (1 ONZ)" "28 g (0.25 cup)" "28 g (0.25 cup)" ...
 $ no_nutriments                             : logi [1:35000] NA NA NA NA NA NA ...
 $ additives_n                               : num [1:35000] NA 0 0 0 0 0 0 1 0 0 ...
 $ additives                                 : chr [1:35000] NA "[ bananas -> en:bananas  ]  [ vegetable-oil -> en:vegetable-oil  ]  [ oil -> en:oil  ]  [ coconut-oil -> en:coc"| __truncated__ "[ peanuts -> en:peanuts  ]  [ wheat-flour -> en:wheat-flour  ]  [ flour -> en:flour  ]  [ sugar -> en:sugar  ] "| __truncated__ "[ organic-hazelnuts -> en:organic-hazelnuts  ]  [ hazelnuts -> en:hazelnuts  ]  [ organic-cashews -> en:organic"| __truncated__ ...
 $ additives_tags                            : chr [1:35000] NA NA NA NA ...
 $ additives_en                              : chr [1:35000] NA NA NA NA ...
 $ ingredients_from_palm_oil_n               : num [1:35000] NA 0 0 0 0 0 0 0 0 0 ...
 $ ingredients_from_palm_oil                 : logi [1:35000] NA NA NA NA NA NA ...
 $ ingredients_from_palm_oil_tags            : chr [1:35000] NA NA NA NA ...
 $ ingredients_that_may_be_from_palm_oil_n   : num [1:35000] NA 0 0 0 0 0 0 0 0 0 ...
 $ ingredients_that_may_be_from_palm_oil     : logi [1:35000] NA NA NA NA NA NA ...
 $ ingredients_that_may_be_from_palm_oil_tags: chr [1:35000] NA NA NA NA ...
 $ nutrition_grade_uk                        : logi [1:35000] NA NA NA NA NA NA ...
 $ nutrition_grade_fr                        : chr [1:35000] NA "d" "b" "d" ...
 $ pnns_groups_1                             : chr [1:35000] NA NA NA NA ...
 $ pnns_groups_2                             : chr [1:35000] NA NA NA NA ...
 $ states                                    : chr [1:35000] "en:to-be-completed, en:nutrition-facts-to-be-completed, en:ingredients-to-be-completed, en:expiration-date-to-b"| __truncated__ "en:to-be-completed, en:nutrition-facts-completed, en:ingredients-completed, en:expiration-date-to-be-completed,"| __truncated__ "en:to-be-completed, en:nutrition-facts-completed, en:ingredients-completed, en:expiration-date-to-be-completed,"| __truncated__ "en:to-be-completed, en:nutrition-facts-completed, en:ingredients-completed, en:expiration-date-to-be-completed,"| __truncated__ ...
 $ states_tags                               : chr [1:35000] "en:to-be-completed,en:nutrition-facts-to-be-completed,en:ingredients-to-be-completed,en:expiration-date-to-be-c"| __truncated__ "en:to-be-completed,en:nutrition-facts-completed,en:ingredients-completed,en:expiration-date-to-be-completed,en:"| __truncated__ "en:to-be-completed,en:nutrition-facts-completed,en:ingredients-completed,en:expiration-date-to-be-completed,en:"| __truncated__ "en:to-be-completed,en:nutrition-facts-completed,en:ingredients-completed,en:expiration-date-to-be-completed,en:"| __truncated__ ...
 $ states_en                                 : chr [1:35000] "To be completed,Nutrition facts to be completed,Ingredients to be completed,Expiration date to be completed,Cha"| __truncated__ "To be completed,Nutrition facts completed,Ingredients completed,Expiration date to be completed,Packaging-code-"| __truncated__ "To be completed,Nutrition facts completed,Ingredients completed,Expiration date to be completed,Packaging-code-"| __truncated__ "To be completed,Nutrition facts completed,Ingredients completed,Expiration date to be completed,Packaging-code-"| __truncated__ ...
 $ main_category                             : chr [1:35000] NA NA NA NA ...
 $ main_category_en                          : chr [1:35000] NA NA NA NA ...
 $ image_url                                 : chr [1:35000] NA NA NA NA ...
 $ image_small_url                           : chr [1:35000] NA NA NA NA ...
 $ energy_100g                               : num [1:35000] NA 2243 1941 2540 1552 ...
 $ energy-from-fat_100g                      : num [1:35000] NA NA NA NA NA NA NA NA NA NA ...
 $ fat_100g                                  : num [1:35000] NA 28.57 17.86 57.14 1.43 ...
 $ saturated-fat_100g                        : num [1:35000] NA 28.57 0 5.36 NA ...
 $ -butyric-acid_100g                        : logi [1:35000] NA NA NA NA NA NA ...
 $ -caproic-acid_100g                        : logi [1:35000] NA NA NA NA NA NA ...
 $ -caprylic-acid_100g                       : logi [1:35000] NA NA NA NA NA NA ...
 $ -capric-acid_100g                         : logi [1:35000] NA NA NA NA NA NA ...
 $ -lauric-acid_100g                         : logi [1:35000] NA NA NA NA NA NA ...
 $ -myristic-acid_100g                       : logi [1:35000] NA NA NA NA NA NA ...
 $ -palmitic-acid_100g                       : logi [1:35000] NA NA NA NA NA NA ...
 $ -stearic-acid_100g                        : logi [1:35000] NA NA NA NA NA NA ...
 $ -arachidic-acid_100g                      : logi [1:35000] NA NA NA NA NA NA ...
 $ -behenic-acid_100g                        : logi [1:35000] NA NA NA NA NA NA ...
 $ -lignoceric-acid_100g                     : logi [1:35000] NA NA NA NA NA NA ...
 $ -cerotic-acid_100g                        : logi [1:35000] NA NA NA NA NA NA ...
 $ -montanic-acid_100g                       : logi [1:35000] NA NA NA NA NA NA ...
 $ -melissic-acid_100g                       : logi [1:35000] NA NA NA NA NA NA ...
 $ monounsaturated-fat_100g                  : num [1:35000] NA NA NA NA NA NA NA NA NA NA ...
 $ polyunsaturated-fat_100g                  : num [1:35000] NA NA NA NA NA NA NA NA NA NA ...
 $ omega-3-fat_100g                          : logi [1:35000] NA NA NA NA NA NA ...
 $ -alpha-linolenic-acid_100g                : logi [1:35000] NA NA NA NA NA NA ...
 $ -eicosapentaenoic-acid_100g               : logi [1:35000] NA NA NA NA NA NA ...
 $ -docosahexaenoic-acid_100g                : logi [1:35000] NA NA NA NA NA NA ...
 $ omega-6-fat_100g                          : logi [1:35000] NA NA NA NA NA NA ...
 $ -linoleic-acid_100g                       : logi [1:35000] NA NA NA NA NA NA ...
 $ -arachidonic-acid_100g                    : logi [1:35000] NA NA NA NA NA NA ...
 $ -gamma-linolenic-acid_100g                : logi [1:35000] NA NA NA NA NA NA ...
 $ -dihomo-gamma-linolenic-acid_100g         : logi [1:35000] NA NA NA NA NA NA ...
 $ omega-9-fat_100g                          : logi [1:35000] NA NA NA NA NA NA ...
 $ -oleic-acid_100g                          : logi [1:35000] NA NA NA NA NA NA ...
 $ -elaidic-acid_100g                        : logi [1:35000] NA NA NA NA NA NA ...
 $ -gondoic-acid_100g                        : logi [1:35000] NA NA NA NA NA NA ...
 $ -mead-acid_100g                           : logi [1:35000] NA NA NA NA NA NA ...
 $ -erucic-acid_100g                         : logi [1:35000] NA NA NA NA NA NA ...
 $ -nervonic-acid_100g                       : logi [1:35000] NA NA NA NA NA NA ...
  [list output truncated]
 - attr(*, "spec")=
  .. cols(
  ..   code = col_character(),
  ..   url = col_character(),
  ..   creator = col_character(),
  ..   created_t = col_double(),
  ..   created_datetime = col_datetime(format = ""),
  ..   last_modified_t = col_double(),
  ..   last_modified_datetime = col_datetime(format = ""),
  ..   product_name = col_character(),
  ..   generic_name = col_character(),
  ..   quantity = col_character(),
  ..   packaging = col_character(),
  ..   packaging_tags = col_character(),
  ..   brands = col_character(),
  ..   brands_tags = col_character(),
  ..   categories = col_character(),
  ..   categories_tags = col_character(),
  ..   categories_en = col_character(),
  ..   origins = col_character(),
  ..   origins_tags = col_character(),
  ..   manufacturing_places = col_character(),
  ..   manufacturing_places_tags = col_character(),
  ..   labels = col_character(),
  ..   labels_tags = col_character(),
  ..   labels_en = col_character(),
  ..   emb_codes = col_character(),
  ..   emb_codes_tags = col_character(),
  ..   first_packaging_code_geo = col_logical(),
  ..   cities = col_logical(),
  ..   cities_tags = col_logical(),
  ..   purchase_places = col_character(),
  ..   stores = col_character(),
  ..   countries = col_character(),
  ..   countries_tags = col_character(),
  ..   countries_en = col_character(),
  ..   ingredients_text = col_character(),
  ..   allergens = col_character(),
  ..   allergens_en = col_logical(),
  ..   traces = col_character(),
  ..   traces_tags = col_character(),
  ..   traces_en = col_character(),
  ..   serving_size = col_character(),
  ..   no_nutriments = col_logical(),
  ..   additives_n = col_double(),
  ..   additives = col_character(),
  ..   additives_tags = col_character(),
  ..   additives_en = col_character(),
  ..   ingredients_from_palm_oil_n = col_double(),
  ..   ingredients_from_palm_oil = col_logical(),
  ..   ingredients_from_palm_oil_tags = col_character(),
  ..   ingredients_that_may_be_from_palm_oil_n = col_double(),
  ..   ingredients_that_may_be_from_palm_oil = col_logical(),
  ..   ingredients_that_may_be_from_palm_oil_tags = col_character(),
  ..   nutrition_grade_uk = col_logical(),
  ..   nutrition_grade_fr = col_character(),
  ..   pnns_groups_1 = col_character(),
  ..   pnns_groups_2 = col_character(),
  ..   states = col_character(),
  ..   states_tags = col_character(),
  ..   states_en = col_character(),
  ..   main_category = col_character(),
  ..   main_category_en = col_character(),
  ..   image_url = col_character(),
  ..   image_small_url = col_character(),
  ..   energy_100g = col_double(),
  ..   `energy-from-fat_100g` = col_double(),
  ..   fat_100g = col_double(),
  ..   `saturated-fat_100g` = col_double(),
  ..   `-butyric-acid_100g` = col_logical(),
  ..   `-caproic-acid_100g` = col_logical(),
  ..   `-caprylic-acid_100g` = col_logical(),
  ..   `-capric-acid_100g` = col_logical(),
  ..   `-lauric-acid_100g` = col_logical(),
  ..   `-myristic-acid_100g` = col_logical(),
  ..   `-palmitic-acid_100g` = col_logical(),
  ..   `-stearic-acid_100g` = col_logical(),
  ..   `-arachidic-acid_100g` = col_logical(),
  ..   `-behenic-acid_100g` = col_logical(),
  ..   `-lignoceric-acid_100g` = col_logical(),
  ..   `-cerotic-acid_100g` = col_logical(),
  ..   `-montanic-acid_100g` = col_logical(),
  ..   `-melissic-acid_100g` = col_logical(),
  ..   `monounsaturated-fat_100g` = col_double(),
  ..   `polyunsaturated-fat_100g` = col_double(),
  ..   `omega-3-fat_100g` = col_logical(),
  ..   `-alpha-linolenic-acid_100g` = col_logical(),
  ..   `-eicosapentaenoic-acid_100g` = col_logical(),
  ..   `-docosahexaenoic-acid_100g` = col_logical(),
  ..   `omega-6-fat_100g` = col_logical(),
  ..   `-linoleic-acid_100g` = col_logical(),
  ..   `-arachidonic-acid_100g` = col_logical(),
  ..   `-gamma-linolenic-acid_100g` = col_logical(),
  ..   `-dihomo-gamma-linolenic-acid_100g` = col_logical(),
  ..   `omega-9-fat_100g` = col_logical(),
  ..   `-oleic-acid_100g` = col_logical(),
  ..   `-elaidic-acid_100g` = col_logical(),
  ..   `-gondoic-acid_100g` = col_logical(),
  ..   `-mead-acid_100g` = col_logical(),
  ..   `-erucic-acid_100g` = col_logical(),
  ..   `-nervonic-acid_100g` = col_logical(),
  ..   `trans-fat_100g` = col_double(),
  ..   cholesterol_100g = col_double(),
  ..   carbohydrates_100g = col_double(),
  ..   sugars_100g = col_double(),
  ..   `-sucrose_100g` = col_logical(),
  ..   `-glucose_100g` = col_logical(),
  ..   `-fructose_100g` = col_logical(),
  ..   `-lactose_100g` = col_double(),
  ..   `-maltose_100g` = col_logical(),
  ..   `-maltodextrins_100g` = col_logical(),
  ..   starch_100g = col_double(),
  ..   polyols_100g = col_logical(),
  ..   fiber_100g = col_double(),
  ..   proteins_100g = col_double(),
  ..   casein_100g = col_logical(),
  ..   `serum-proteins_100g` = col_logical(),
  ..   nucleotides_100g = col_logical(),
  ..   salt_100g = col_double(),
  ..   sodium_100g = col_double(),
  ..   alcohol_100g = col_logical(),
  ..   `vitamin-a_100g` = col_double(),
  ..   `beta-carotene_100g` = col_logical(),
  ..   `vitamin-d_100g` = col_double(),
  ..   `vitamin-e_100g` = col_double(),
  ..   `vitamin-k_100g` = col_double(),
  ..   `vitamin-c_100g` = col_double(),
  ..   `vitamin-b1_100g` = col_double(),
  ..   `vitamin-b2_100g` = col_double(),
  ..   `vitamin-pp_100g` = col_double(),
  ..   `vitamin-b6_100g` = col_double(),
  ..   `vitamin-b9_100g` = col_double(),
  ..   folates_100g = col_double(),
  ..   `vitamin-b12_100g` = col_double(),
  ..   biotin_100g = col_logical(),
  ..   `pantothenic-acid_100g` = col_double(),
  ..   silica_100g = col_logical(),
  ..   bicarbonate_100g = col_logical(),
  ..   potassium_100g = col_double(),
  ..   chloride_100g = col_logical(),
  ..   calcium_100g = col_double(),
  ..   phosphorus_100g = col_double(),
  ..   iron_100g = col_double(),
  ..   magnesium_100g = col_double(),
  ..   zinc_100g = col_double(),
  ..   copper_100g = col_double(),
  ..   manganese_100g = col_double(),
  ..   fluoride_100g = col_logical(),
  ..   selenium_100g = col_double(),
  ..   chromium_100g = col_logical(),
  ..   molybdenum_100g = col_logical(),
  ..   iodine_100g = col_logical(),
  ..   caffeine_100g = col_logical(),
  ..   taurine_100g = col_logical(),
  ..   ph_100g = col_logical(),
  ..   `fruits-vegetables-nuts_100g` = col_logical(),
  ..   `fruits-vegetables-nuts-estimate_100g` = col_double(),
  ..   `collagen-meat-protein-ratio_100g` = col_logical(),
  ..   cocoa_100g = col_logical(),
  ..   chlorophyl_100g = col_logical(),
  ..   `carbon-footprint_100g` = col_logical(),
  ..   `nutrition-score-fr_100g` = col_double(),
  ..   `nutrition-score-uk_100g` = col_double(),
  ..   `glycemic-index_100g` = col_logical(),
  ..   `water-hardness_100g` = col_logical()
  .. )
 - attr(*, "problems")=<externalptr> 

기존 방법은 2.663초, readr 패키지는 4.186초가 소요되었습니다. 데이터의 용량이 그리 크지 않기 때문에 기존 방법의 수행속도가 다소 빠를 수 있지만, 대용량 데이터의 경우에는 readr 패키지의 속도가 빠릅니다.

그리고 35,000건의 데이터 중에서 기존의 방법은 23,179만 읽었을 뿐입니다.

솔루션

파일의 용량이 클 경우에는 readr 패키지를 이용해서 데이터를 읽는 것이 시간을 절약할 수 있는 유용한 방법입니다.