R read.csv() Function - Read CSV Files
R Language ExamplesThe R read.csv() function is used to read CSV (Comma-Separated Values) files into a data frame.
It is the first step in data analysis, and CSV is the most common data exchange format.
The syntax of the read.csv() function is as follows:
read.csv(file, header = TRUE, sep = ",", stringsAsFactors = FALSE)
Parameter description:
fileFile path or URL.
headerWhether the first row is used as column names, default TRUE.
sepSeparator, defaults to comma for csv. read.csv2() uses semicolon.
stringsAsFactorsWhether to convert strings to factors, defaulting to FALSE since R 4.0.
Example
# First create a sample CSV file
df <- data.frame(
Name= c("Zhang San", "Li Si", "Wang Wu"),
Age= c(25, 30, 28),
Score= c(88, 92, 76)
)
write.csv(df, "temp_students.csv", row.names = FALSE)
# Read the CSV file
data <- read.csv("temp_students.csv")
print("Read CSV data:")
print(data)
# View structure
print("Data types:")
print(str(data))
# Specify options when reading
data2 <- read.csv("temp_students.csv",
stringsAsFactors = FALSE)
print("Strings converted to factors:")
print(str(data2))
df <- data.frame(
Name= c("Zhang San", "Li Si", "Wang Wu"),
Age= c(25, 30, 28),
Score= c(88, 92, 76)
)
write.csv(df, "temp_students.csv", row.names = FALSE)
# Read the CSV file
data <- read.csv("temp_students.csv")
print("Read CSV data:")
print(data)
# View structure
print("Data types:")
print(str(data))
# Specify options when reading
data2 <- read.csv("temp_students.csv",
stringsAsFactors = FALSE)
print("Strings converted to factors:")
print(str(data2))
Executing the above code produces the following output:
[1] "读取的 CSV 数据:" 姓名 年龄 成绩 1 张三 25 88 2 李四 30 92 3 王五 28 76Other Extensions