How to read column names and metadata from feather files in R arrow?

To access column names and metadata from feather files in R programming, we use the R Arrow package to load the feather file into a data frame. After loading the feather file, we can retrieve the column names and metadata attributes by using the Feather package. 

What is Arrow Package in R?

The Arrow package available in R offers a range of tools to work with the Arrow and Feather format. The Arrow format enables efficient data interchange between various computing environments and is language-agnostic. It allows sharing of data between diverse platforms and programming languages.

The Arrow format relies on columnar data representation which is memory-efficient and allows for speedy data processing and analysis, unlike the traditional row-oriented formats such as CSV or JSON. The data is stored in a binary format, which makes it more compact and faster to read and write than text-based formats.

The Arrow package provides different functions that help us to work with arrow data. It allows us to read and write files, manipulate arrow data structures like arrays and tables, convert data between the arrow and other formats, etc. It also provides a set of tools to handle the metadata, by helping to attach additional information, such as column names, data types, and other metadata.

What is a Feather File?

Feather is a fast and lightweight file format designed for efficient data storage and interchange between programming languages. It is based on the Apache Arrow specification, which provides a standardized data format for in-memory and disk-based data processing across various programming languages. Feather is a binary file format that has been designed to store data in a columnar layout, and it is an excellent choice for quickly exchanging data between various computing environments.

The Feather package provides functions that are used to read and write feather files and retrieve the metadata of the feather files.

To Read Column Names and Metadata from Feather Files in R Arrow

To read column names and metadata from a feather file, one needs to install and load the arrow and feather packages, which can be done by following the steps mentioned below:

• Installing the required packages

install.packages("arrow")
install.packages("feather")

• Loading the packages in R

library(arrow)
library(feather)

Here’s an example of how to read column names and metadata from a feather file in the R arrow:

R

# installing the requied packages
install.packages("arrow")
install.packages("feather")

# loading the requied packages
library(arrow)
library(feather)

# Write the mtcars dataset to a feather file
write_feather(mtcars, "mtcars.feather")

# Read the feather file and extract column names and metadata
df <- read_feather("mtcars.feather")
colnames <- names(df)

metadata <- feather_metadata("mtcars.feather")

# Print column names and metadata
print(colnames)
print(metadata)

First, we will convert R’s built-in dataset “mtcars” into a feather file ‘mtcars.feather’ by using the write_feather() function of the arrow package. Then we read the feather file using the read_feather() function. The names() function in R is used to get the name of the columns. Then we used the feather package’s feather_metadata() function to read the metadata of the file.

Output:

Column names and Metadata of a Feather file