python で fortran の unformatted で出力した INT32 と REAL64 型のデータを読み出す

README.md

gist.20201227.02

目的

fortran から unformatted で出力した INT32 と REAL64 型のデータを python で読み出す方法の確認。

実行方法

make
python3 ./main.py

実行結果

order:  C
major:  col
<__main__.TestData object at 0x7f0e685964a8>
<class '__main__.TestData'>
[[ 1.  5.  9.]
 [ 2.  6. 10.]
 [ 3.  7. 11.]
 [ 4.  8. 12.]]

order:  C
major:  row
<__main__.TestData object at 0x7f0e68483550>
<class '__main__.TestData'>
[[ 1.  4.  7. 10.]
 [ 2.  5.  8. 11.]
 [ 3.  6.  9. 12.]]

order:  F
major:  col
<__main__.TestData object at 0x7f0e4f6c6e48>
<class '__main__.TestData'>
[[ 1.  5.  9.]
 [ 2.  6. 10.]
 [ 3.  7. 11.]
 [ 4.  8. 12.]]

order:  F
major:  row
<__main__.TestData object at 0x7f0e68483550>
<class '__main__.TestData'>
[[ 1.  4.  7. 10.]
 [ 2.  5.  8. 11.]
 [ 3.  6.  9. 12.]]

main.f08

program main

    ! <module>s to import
    use, intrinsic :: iso_fortran_env

    ! require all variables to be explicitly declared
    implicit none

    ! constant(s) for this <program>
    integer(INT32), parameter :: num_col  = 4_INT32
    integer(INT32), parameter :: num_row  = 3_INT32
    integer(INT32), parameter :: len_data = num_col * num_row

    ! variable(s) for this <program>
    integer        :: save_unit_ascii
    integer        :: save_unit_binary
    integer(INT32) :: itr
    real(REAL64)   :: test_data(len_data)

    ! STEP.01
    ! generate test data
    test_data(:) = (/ (itr * 1.0_REAL64, itr = 1_INT32, len_data, 1_INT32) /)

    ! STEP.02
    ! open a file to save test data
    open(&!
        action  = 'write'         , &!
        file    = 'ascii.dat'     , &!
        form    = 'formatted'     , &!
        newunit = save_unit_ascii , &!
        status  = 'replace'         &!
    )

    open(&!
        access  = 'stream'         , &!
        action  = 'write'          , &!
        file    = 'binary.dat'     , &!
        form    = 'unformatted'    , &!
        newunit = save_unit_binary , &!
        status  = 'replace'          &!
    )

    ! STEP.03.01
    ! write the test data (ascii)
    write(unit= save_unit_ascii, fmt='(I0)')        num_row
    write(unit= save_unit_ascii, fmt='(I0)')        num_col
    write(unit= save_unit_ascii, fmt='(ES24.16E3)') test_data(:)

    ! STEP.03.02
    ! write the test data (binary)
    write(unit= save_unit_binary) num_row
    write(unit= save_unit_binary) num_col
    write(unit= save_unit_binary) test_data(:)

    ! STEP.04
    ! close the file written the test data
    close( unit= save_unit_ascii  , status= 'keep' )
    close( unit= save_unit_binary , status= 'keep' )

end program main

main.py

# -*- coding: utf-8 -*-

# modules to import
import numpy


# local functions

def read_int32(file_stream):
    return numpy.fromfile(file= file_stream, dtype= numpy.int32, count=1)[0]


def read_real64(file_stream):
    return numpy.fromfile(file= file_stream, dtype= numpy.float64, count=1)[0]


class TestData:

    class Shape:

        def __init__(self, file_stream, order, major):
            self.row   = read_int32(file_stream= file_stream)
            self.col   = read_int32(file_stream= file_stream)
            self.order = order
            self.major = major
            pass


        def get_shape(self):
            if self.major == 'col':
                return self.get_shape_major_col()
            elif self.major == 'row':
                return self.get_shape_major_row()
            else:
                pass


        def get_shape_major_col(self):
            return (self.col, self.row)


        def get_shape_major_row(self):
            return (self.row, self.col)


    def __init__(self, file_path, order, major):

        with open(file_path, 'rb') as self.file_stream:

            # STEP.01
            # get the test data shape
            self.shape = TestData.Shape(file_stream= self.file_stream, order= order, major= major)

            # STEP.02
            # prepare the numpy.array object to store the test data
            self.array = numpy.zeros( shape= self.shape.get_shape() , dtype= numpy.float64, order= order )

            # STEP.03
            # read out the test data
            if major == 'col':

                for itr_row in range(self.shape.row):
                    for itr_col in range(self.shape.col):
                        self.array[itr_col, itr_row] = read_real64(file_stream= self.file_stream)

            elif major == 'row':

                for itr_col in range(self.shape.col):
                    for itr_row in range(self.shape.row):
                        self.array[itr_row, itr_col] = read_real64(file_stream= self.file_stream)

            else:
                pass

            # STEP.END
            pass


    def show(self):
        print()
        print( 'order: ', self.shape.order )
        print( 'major: ', self.shape.major )
        print( test_data )
        print( type(test_data) )
        print( test_data.array )
        pass


# main process is as follows


if __name__ == "__main__":
    
    test_data = TestData(file_path= './binary.dat', order= 'C', major= 'col'); test_data.show()
    test_data = TestData(file_path= './binary.dat', order= 'C', major= 'row'); test_data.show()
    test_data = TestData(file_path= './binary.dat', order= 'F', major= 'col'); test_data.show()
    test_data = TestData(file_path= './binary.dat', order= 'F', major= 'row'); test_data.show()

    pass


# EOF

Makefile

FCFLAGS= -fbacktrace -fbounds-check -ffree-line-length-none -O2 -pedantic -std=f2008 -Wall -Wextra

main.exe: ./main.f08
	gfortran $(FCFLAGS) -o ./main.exe $<

clean:
	rm ./*.mod ./*.o ./*.dat