lsofj.py

import json
import sys

head = sys.stdin.readline().strip()
cols = [x for x in head.split(" ") if x]
col_end = {col: head.find(col)+len(col) for col in cols}

def get_col(line, c):
    if c == cols[0]:
        if line[0] == " ":
            return None
        return line[:line.find(" ")]

    if c == cols[-1]:
        offset = col_end[c] - len(c)
        if offset >= len(line) or line[offset] == " ":
            return None
        return line[offset:].strip()

    if c in col_end:
        x = line[:col_end[c]+1]
        if x[-2]== " ":
            return None
        else:
            return x[x.strip().rfind(" ")+1:].strip()

if len(sys.argv) == 1:
    print(head)
else:
    selected = sys.argv[1:]
    for x in sys.stdin:
        row = {col: get_col(x, col) for col in selected}
        print(json.dumps(row))