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RData Format

Description​

RData (.rdata or .RData) is R's native binary format for saving multiple R objects. It's commonly used in R statistical computing to save workspace data, including data frames, vectors, lists, and other R objects. This implementation supports reading RData files and converting them to Python dictionaries.

File Extensions​

  • .rdata - RData files
  • .RData - RData files (case-sensitive variant)
  • .rda - RData files (alias)

Implementation Details​

Reading​

The RData implementation:

  • Uses pyreadr library for reading
  • Reads RData files which can contain multiple R objects
  • Converts data frames to pandas DataFrames, then to dictionaries
  • When multiple objects are present, adds _r_object_name metadata field to identify the source object
  • Requires file path (not stream)

Writing​

Writing is not currently supported for RData format.

Key Features​

  • Multiple objects: Can contain multiple R objects in a single file
  • Statistical format: Designed for R statistical computing
  • Totals support: Can count total rows across all objects
  • Type preservation: Maintains data types from R
  • Object identification: When multiple objects exist, adds metadata to identify source

Usage​

from iterable import open_iterable

# List available R objects
from iterable.datatypes.rdata import RDataIterable

# Discover R objects before opening
objects = RDataIterable('data.rdata').list_tables('data.rdata')
print(f"Available R objects: {objects}")  # e.g., ['df1', 'df2', 'vector1']

# Basic reading
source = open_iterable('data.rdata')
for row in source:
    print(row)
source.close()

Parameters​

No specific parameters required.

Limitations​

  1. Read-only: RData format does not support writing
  2. pyreadr dependency: Requires pyreadr package
  3. File path required: Requires filename, not stream
  4. Flat data only: Only supports tabular data (data frames)
  5. Memory usage: Entire file is loaded into memory
  6. Multiple objects: When file contains multiple objects, they are flattened into a single stream

Compression Support​

RData files can be compressed with all supported codecs:

  • GZip (.rdata.gz)
  • BZip2 (.rdata.bz2)
  • LZMA (.rdata.xz)
  • LZ4 (.rdata.lz4)
  • ZIP (.rdata.zip)
  • Brotli (.rdata.br)
  • ZStandard (.rdata.zst)

Use Cases​

  • Statistical analysis: Working with R data files
  • Data migration: Converting R data to other formats
  • Research data: Processing research datasets in R format
  • Academic research: Common in academic research and data science
  • R workspace files: Reading saved R workspace files
  • RDS - R's single object format
  • SAS - SAS statistical format
  • Stata - Stata statistical format
  • SPSS - SPSS statistical format
  • CSV - Simple text format for conversion