page count

pc

#!/usr/bin/env python
from argparse import ArgumentParser, ArgumentTypeError
from subprocess import check_output
from sys import exit, stdout


def format_count(count, scale):
    return f'%.{scale}f' % count


def format_line(count, filename):
    return '{:>8} {}'.format(count, filename)


def mk_min_arg(prefix, type, min):
    def min_arg(value):
        value = type(value)
        if value < min:
            raise ArgumentTypeError(f'{prefix} value must be {min} or greater.')
        return value
    return min_arg


def parse_args():
    parser = ArgumentParser()
    parser.add_argument(
        'filenames',
        nargs='*',
        default=['-'],
        help='file names or none for stdin'
    )
    parser.add_argument(
        '--size',
        default=300,
        type=mk_min_arg('size', int, min=1),
        help='size of page, 1 or greater, default=300'
    )
    parser.add_argument(
        '--scale',
        default=1,
        type=mk_min_arg('scale', int, min=0),
        help='decimal scale, 0 or greater, default=1'
    )
    return parser.parse_args()


def output_line(value, scale, name, file=None):
    file = stdout if file == None else file
    print(format_line(format_count(value, scale), name), file=file)


def count_pages(filename, size, positive_size=mk_min_arg('size', int, min=1)):
    output = check_output(f"wc -w {filename} | awk '{{print $1}}'", shell=True)
    return float(output) / positive_size(size)


def count_pages_command(filenames, size, scale):
    total = 0
    for filename in filenames:
        pages = count_pages('' if filename == '-' else filename, size=size)
        total += pages
        output_line(pages, scale, '<stdin>' if filename == '-' else filename)
    output_line(total, scale, 'total')


if __name__ == '__main__':
    try:
        count_pages_command(**parse_args().__dict__)
    except (KeyboardInterrupt, ):
        exit(1)