$  python ./side-by-side.py --width 40 /tmp/afile.txt /tmp/afile2.txt
this is a file                           |  i have here another file
that has lines of                        |  that also has some text and
text.  to read                           |  some lines.  although it
                                         |  is slightly longer than the other
this is a really really really really re *  file with all these words
                                         |  in
                                         |  it

#!/usr/bin/python

import sys, os
from optparse import OptionParser

class InFile:
    def __init__(self, filename):
        try:
            self.lines=[]
            self.maxlen = 0
            for l in open(filename).readlines():
                self.lines.append(l.rstrip())
        except IOError, (error, message):
            print "Can't read input %s : %s" % (filename, message)
            sys.exit(1)

        self.nlines = len(self.lines)
        if self.nlines == 0:
            self.lines.append("")
        self.maxlen = max(map(len, self.lines))

    # pad to the max len, with a extra space then the deliminator
    def pad_lines(self, nlines, width=0, nodiv=False, notrunc=False):
        if width == 0:
            width = self.maxlen
        pad = []
        for i in range(0, width):
            pad += " "
        # add on some extra for the divider and spaces
        pad += "   "
        padlen = len(pad)
        for i in range(0, nlines):
            try:
                linelen = len(self.lines[i])
            except IndexError:
                self.lines.append("")
                linelen = 0
            if (linelen > width):
                linelen = width
                if not notrunc:
                    pad[-2] = "*"
            elif nodiv:
                pad[-2] = " "
            else:
                pad[-2] = "|"
            self.lines[i] = self.lines[i][:linelen] +  "".join(pad[linelen - padlen:])

usage= "side-by-side [-w width] file1 file2 ... filen"

parser = OptionParser(usage, version=".1")

parser.add_option("-w", "--width", dest="width", action="store", type="int",
                      help="Set fixed width for each file", default=0)
parser.add_option("--last-div", dest="lastdiv", action="store_true",
                  help="Print divider after last file", default=False)
parser.add_option("--no-div", dest="nodiv", action="store_true",
                  help="Don't print any divider characters", default=False)
parser.add_option("--no-trunc", dest="notrunc", action="store_true",
                  help="Don't show truncation with a '*'", default=False)

(options, args) = parser.parse_args()

flist = []
if (len(args) == 0):
    print usage
    sys.exit(1)
for f in args:
    flist.append(InFile(f))

max_lines = max(map(lambda f: f.nlines, flist))

for i in range(0,len(flist)):
    if (len(flist)-1 == i):
        options.nodiv = not options.lastdiv
    flist[i].pad_lines(max_lines, options.width, options.nodiv, options.notrunc)

for l in range(0, max_lines):
    for f in flist:
        print f.lines[l],
    print

pr -Tm file1 file2