sortdf.py

#!/usr/bin/python3.14
import sys
from os.path import realpath, basename
from rich import print as rprint
from pandas import read_csv
from argparse import ArgumentParser, Namespace
from contextlib import redirect_stdout

def add_sort_arguments() -> ArgumentParser:
    p = ArgumentParser()
    p.add_argument('--file', '-f', default="/dev/stdin")
    p.add_argument('--out',  '-o', default=None)
    p.add_argument('--column', '-c', type=int, default=1)
    p.add_argument('--header', '-hdr', default=None, action='store_true')
    p.add_argument('--reverse', '-r', default=False, action='store_true')
    p.add_argument('--separator', '-s', default='\\s+')
    return p

def print_result(df, r, sep, header):
    if '\\' == sep[0]:
        sep = ' '
    if header:
        columns=df.columns.tolist()
        [print(f"{column}{sep}",end="") for column in columns[:-1]]
        print(columns[-1])
    [print(*row, sep=sep) for row in r]

def sort_dataframe(args: Namespace) -> int:
    script_name = basename(realpath(sys.argv[0]))
    try:
        df = read_csv(args.file,sep=args.separator) \
             if args.header else read_csv(args.file,sep=args.separator,header=None) 
        r = df.sort_values(by = df.columns[args.column-1], ascending = not args.reverse).values.tolist() 
        if args.out is not None:
            with open(args.out, 'w') as outf, redirect_stdout(outf):
                print_result(df, r, args.separator, args.header)
        else:
            print_result(df, r, args.separator, args.header)
        return 0

    except Exception as err:
        rprint(f"\n[magenta]{script_name}:[red] ERROR: {err}[/red]\n")
        return 1

if __name__ == '__main__':
    exit(sort_dataframe(add_sort_arguments().parse_args()))

test.csv

test_df.py

import sys
from sortdf import sort_dataframe, add_sort_arguments
from os import remove, popen, getenv
from os.path import exists, dirname, realpath

def test_df(monkeypatch, request):
    root_dir = str(request.config.rootpath) + '/'
    with monkeypatch.context() as m:
        test_path = dirname(realpath(root_dir + getenv('PYTEST_CURRENT_TEST').split(':')[0]))
        out = test_path + '/test.out'
        if exists(out):
            remove(out)
        assert exists(out) == False
        print("")
        m.setattr(sys, 'argv', ['sortdf', '-hdr', '-s,', '-r', '-c2', '-f', test_path + '/test.csv', '-o', out])
        assert sort_dataframe(add_sort_arguments().parse_args()) == 0
        assert int(popen(f"sum {out}").read().split()[0]) == 53966