Python script to decompile ZX-Spectrum BASIC to text using tzxtools library

sinclair_basic2ascii.py

#!/usr/bin/env python3

import argparse
import sys

from tzxlib.convert import convertToBasic

def main():
   parser = argparse.ArgumentParser(description='Convert Sinclair Basic code representation into Text')
   parser.add_argument('file',
               nargs='?',
               type=argparse.FileType('rb'),
               default=(None if sys.stdin.isatty() else sys.stdin.buffer),
               help='Input file, stdin if omitted')
   parser.add_argument('-o', '--to',
               dest='to',
               metavar='TARGET',
               type=argparse.FileType('wb'),
               default=sys.stdout.buffer,
               help='Target text file, stdout if omitted')
   args = parser.parse_args()


   if args.file is None:
       parser.print_help(sys.stderr)
       sys.exit(1)


   args = parser.parse_args()
   data = bytearray(args.file.read())
   convertToBasic(data,args.to)


if __name__ == "__main__":
   main()

listbasic from the fuse emulator will also do this.

You can do the reverse (BASIC source → .tap or .p) using zmakebas.