R中的只读文件头

在本文中，我们将看到 R 编程语言中的文件头。

方法一：使用 read.table 方法

R 中的 read.table() 方法用于访问存储在 CSV 文件的组织结构中的内容。

Syntax: read.table(path, head = TRUE, nrows, sep = “;”)

Arguments:

• path: The complete directory path where the file is stored
• head: a logical value, indicator of whether the file contains the names of the variables as its first line or not.
• nrows: the maximum number of rows to read into the working directory

代码：

R

# creating a data frame
data_frame1 <- data.frame(col1 = c(6:8),
                          col2 = letters[1:3],
                          col3 = c(1,4,NA))
  
# speicfying data path
path <- "/Users/mallikagupta/Desktop/rcontent.csv"
  
# writing data to csv
write.csv2(data_frame1,                   
           path,
           row.names = FALSE)
# reading 
read.table(path,             
           head = TRUE,
           nrows = 1,
           sep = ";")[- 1, ]

输出

[1] col1 col2 col3
<0 rows> (or 0-length row.names)

方法二：使用 colnames 方法

R 中的 read.csv2() 方法用于将 CSV 文件从指定的路径参数读取到表格结构中。

Syntax: read.csv2(path)

Arguments :

path: The complete directory path where the file is stored

基础 R 中的 colnames() 方法用于收集分配给 CSV 文件的表格结构的列名。它将从文件中读取的表格结构作为参数。

Syntax: colnames(df)

Arguments :

df: The data frame to read the header of

代码：

电阻

# creating a data frame
data_frame1 <- data.frame(col1 = c(6:8),
                          col2 = letters[1:3],
                          col3 = c(1,4,NA))
  
# speicfying data path
path <- "/Users/mallikagupta/Desktop/rcontent.csv"
  
# writing data to csv
write.csv2(data_frame1,                   
           path,
           row.names = FALSE)
  
# reading header
colnames(read.csv2(path))

输出

[1] "col1" "col2" "col3"