Fortio

A Python IO for Fortran Unformatted Binary Files with Variable-Length Records.

Features

• read and write Fortran unformatted file
• auto-detect endianness(byteorder)
• allow reading data into pre-allocated buffers
• allow skipping over records or jumping to wanted record directly without reading data
• support subrecords (which is necessary for long record whose size larger than 4GB with signed 4 bytes integer header)
• support numpy.memmap array for fast loading

Installation

pip install fortio

Usage

from fortio import FortranFile
with FortranFile(filename) as f:
    a = f.read_record('i4')
    f.skip_record()
    b = f.read_record('f8')

Read file that contains subrecords (e.g., records greater than 4GB) by setting signed header,

with FortranFile(filename, header_dtype='int32') as f:
    ...

Please read the docstring of FortranFile for detailed documentation.

Functions

• FortranFile(filename, mode='r', header_dtype='uint32', auto_endian=True, check_file=True)

• methods

  • write_record(data)
  • read_record(dtype='byte', shape=None, rec=None, memmap=False)
  • mmap_record(dtype='byte', shape=None, rec=None)
  • read_record_into(into, offset=None, rec=None)
  • get_record_size(rec=None)
  • skip_record(nrec=1)
  • goto_record(rec=None)
  • close()
  • flush()

• properties

  • file
  • filesize
  • mode
  • header_dtype
  • long_records
  • closed
  • byteorder

• internal properties and methods

  • _fp
  • _offsets
  • _lengths
  • _read_header()
  • _check_byteorder()
  • _check_file()
  • _read_record_data(data)