read.csv() Function in R: How to Read CSV File in R

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R is a statistical language, and you often came across the external dataset built on text files.  In R, we can read data from files stored outside the R environment. One of the easiest and most reliable ways of getting data into R is to use text files, in particular CSV (comma-separated values) files.

The CSV file format uses commas to separate the different elements in a line, and each line of data is in its own line in the text file, which makes CSV files ideal for representing tabular data.

How to Read CSV File in R

To read a CSV file in R, use the read.csv() function. The read.csv() function is used to read the CSV file available in your current working directory. You can check which directory the R workspace is pointing to using the getwd() function. You can also set a new working directory using the setwd() function.

Syntax

read.csv("path to csv file")

Parameters

The read.csv() function takes a csv file or path to the csv file. The read.csv() function has several arguments, but the only essential argument is a file, which specifies the location and filename.

Example

data <- read.csv("cuisine.csv")
data

Output

    placeID  Rcuisine
910 132006   Dutch-Belgian
911 132005   French
912 132005   Seafood
913 132004   Seafood
914 132003   International
915 132002   Seafood
916 132001   Dutch-Belgian

By default, the read.csv() function gives the output as a data frame. This can be easily checked as follows. Also, we can check the number of columns and rows.

To check if the output is data frame, use the is.data.frame() function.

To get the number of columns of the data frame, use the ncol() function.

To get the number of rows of the data frame, use the nrow() function.

data <- read.csv("cuisine.csv")
is.data.frame(data)
ncol(data)
nrow(data)

Output

[1] TRUE
[1] 2
[1] 916

That is it for reading the csv file in the R language.

See also

write.csv() in R

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