Sort a file by an indexfile which defines the order; http://forum.ubuntuusers.de/topic/logische-zusammenfuegen-von-2-dateien/

data.txt

Tobi Testperson  7 38
MaxMusterPerson3 5 12
NachnamePerson3 43 23

index.txt

MaxMusterPerson3
Tobi Testperson
NachnamePerson3

Output

./sort.py index.txt < data.txt
MaxMusterPerson3 5 12
Tobi Testperson 7 38
NachnamePerson3 43 23

sorter.py

#!/usr/bin/env python2
# coding: utf-8

import sys
import argparse
from contextlib import closing
from collections import defaultdict


def read_index(fileobj):
    with closing(fileobj):
        for line in fileobj:
            yield line.strip()
        
        
def parse_data(fileobj):
    data = defaultdict(list)
    with closing(fileobj):
        for row in fileobj:
            # with Python3 this is much nicer :-)
            #key, *values = row.rsplit(None, 2)
            #data[key] = values
            key, a, b = row.rsplit(None, 2)
            data[key] = [a, b]
    return data
      
    
def save(data, fileobj):
    with closing(fileobj):
        fileobj.write("\n".join(data))
        
        
def sort(index, data):
    for key in index:
        yield "{} {}".format(key, " ".join(data[key]))


def main():
    parser = argparse.ArgumentParser(description="sort a file by an indexfile")
    parser.add_argument("index", type=argparse.FileType("r"))
    parser.add_argument("infile", nargs="?", type=argparse.FileType("r"),  
                        default=sys.stdin)
    parser.add_argument("outfile", nargs="?", type=argparse.FileType("w"),
                        default=sys.stdout)
    
    args = parser.parse_args()
    
    save(sort(read_index(args.index), parse_data(args.infile)), args.outfile)
        
    
if __name__ == "__main__":
    main()