getsection

#!/usr/bin/env python3

"""
Extract one or more sections from an ORG file
"""

import argparse
import sys

if __name__=="__main__":
    # Parse args
    parser = argparse.ArgumentParser(description="Extract one or more sections from an org file, and save or print to stdout")
    parser.add_argument("-i", "--infile", type=str, default=None, help="Org file from which to extract sections, default stdin")
    parser.add_argument("sections", nargs="+", help="One or more sections to extract, in desired order")
    parser.add_argument("-o", "--output", type=str, default=None, help="Output file, default stdout")
    args = parser.parse_args()

    output_lines = []
    # Search for each section, one by one
    for section in args.sections:
        # Open the file afresh for each search
        with (open(args.infile, 'r') if args.infile else sys.stdin) as infile:
            in_target_section = False
            for line in infile:
                # Check if we're at a new section
                split_line = line.split()
                if len(split_line)>1 and split_line[0]=='*':
                    # Have reached a new section
                    if in_target_section:
                        # If we were in the target section previously, we no longer are
                        # Record this section, then break to start looking for next patterns to match
                        output_lines.append('\n')
                        break
                    if split_line[1] == section:
                        in_target_section = True
                if in_target_section:
                    output_lines.append(line)

    if args.output is None:
        print(''.join(output_lines))
    else:
        with open(args.output, 'w') as outfile:
            outfile.write(''.join(output_lines))