學習筆記，僅供參考

---

利用readr和readxl包讀寫數據

讀取數據

• 相關函數

函數包readr和readxl提供了一系列的數據讀入功能，主要函數如下：

#readr包read_delim(file, delim, quote = "\"", escape_backslash = FALSE,escape_double = TRUE, col_names = TRUE, col_types = NULL,locale = default_locale(), na = c("", "NA"), quoted_na = TRUE,comment = "", trim_ws = FALSE, skip = 0, n_max = Inf,guess_max = min(1000, n_max), progress = show_progress(),skip_empty_rows = TRUE)read_csv(file, col_names = TRUE, col_types = NULL,locale = default_locale(), na = c("", "NA"), quoted_na = TRUE,quote = "\"", comment = "", trim_ws = TRUE, skip = 0,n_max = Inf, guess_max = min(1000, n_max),progress = show_progress(), skip_empty_rows = TRUE)#readxl包 read_excel(path, sheet = NULL, range = NULL, col_names = TRUE,col_types = NULL, na = "", trim_ws = TRUE, skip = 0,n_max = Inf, guess_max = min(1000, n_max),progress = readxl_progress(), .name_repair = "unique")read_xls(path, sheet = NULL, range = NULL, col_names = TRUE,col_types = NULL, na = "", trim_ws = TRUE, skip = 0,n_max = Inf, guess_max = min(1000, n_max),progress = readxl_progress(), .name_repair = "unique")

• 參數

• 舉個例子

輸入：

library(readr) library(readxl)cp <-read_delim("comp.csv", ",") cp.csv <- read_csv("comp.csv") cp.xl <- read_excel("comp.xlsx") #summary(cp.csv) #summary(cp.xl)system.time(read_csv("data.csv")) system.time(read.csv("data.csv"))

輸出：

> system.time(read_csv("data.csv")) 用戶 系統 流逝 0.88 0.00 0.89 Warning message: Duplicated column names deduplicated: 'DATE_R' => 'DATE_R_1' [48] > system.time(read.csv("data.csv")) 用戶 系統 流逝 3.77 0.05 3.86

通過與R中的read.csv()函數進行比對，我們發現，利用函數包readr和readxl中的函數進行數據讀入的速度有很大提升。

寫入數據

函數包readr提供了數據讀取功能的同時，還提供了數據寫入功能，即將data.frame對象重新寫為csv, xlsx,等格式的文件。

• 相關函數

write_delim(x, path, delim = " ", na = "NA", append = FALSE,col_names = !append, quote_escape = "double")write_csv(x, path, na = "NA", append = FALSE, col_names = !append,quote_escape = "double")write_excel_csv(x, path, na = "NA", append = FALSE,col_names = !append, delim = ",", quote_escape = "double")

• 參數

• 舉個例子

輸入：

df <- data.frame(x = c(1,2,3,4,5), y = c(6,7,NA,9,0)) write_delim(df, "df1.csv", delim = ",") write_csv(df, "df2.csv", na = "-")

df1.csv：

df2.csv：

總結

以上是生活随笔為你收集整理的R语言观察日志(part5)--利用readr和readxl包读写数据的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。