print_erl_string: a script that reads a text, collects the numbers between 32 and 128, and prints the corresponding ASCII characters.

print_erl_string

#!/usr/bin/env python3

# print_erl_string is a script that reads a text, collects the numbers between
# 32 and 128, and prints the corresponding ASCII characters.
#
# Example:
#
#     $ cat myfile
#     [0,116,104,105,115,32,105,115,32,97,32,116,101,120,116,32,116,104,97,116,
#      32,105,115,32,110,111,116,32,102,111,114,109,97,116,116,101,100,32,97,
#      115,32,97,32,115,116,114,105,110,103,32,98,101,99,97,117,115,101,32,111,
#      102,32,97,32,110,111,110,45,97,115,99,105,105,32,99,104,97,114,97,99,
#      116,101,114]
#
#     $ print_erl_string myfile
#     this is a text that is not formatted as a string because of a non-ascii
#     character
#     $
#
# When no parameter is specified, the script reads text from the standard
# input:
#
#     $ cat myfile | print_erl_string
#     this is a text that is not formatted as a string because of a non-ascii
#     character
#     $

import sys


def w(s):
    sys.stdout.write(s)
    sys.stdout.flush()


def print_num(num):
    if num != 0:
        if 32 <= num <= 127:
            try:
                w(chr(num))
            except:
                pass
        else:
            w('_')


def print_erl_string_fd(f):
    num = 0
    while True:
        ch = f.read(1)
        if ch == '':
            break
        o = ord(ch)
        if 48 <= o <= 57:
            num = num * 10 + (o - 48)
        else:
            print_num(num)
            num = 0
    print_num(num)


if len(sys.argv) > 1:
    with open(sys.argv[1]) as f:
        print_erl_string_fd(f)
else:
    print_erl_string_fd(sys.stdin)

w('\n')