union in Python

[Wiebke Pätzold]

Hi all, 

about union I found still something else. Perhaps it is better. But
here the program doesn't run too.
Can me somebody help?

import sys
import Mk4py
import re

db = Mk4py.storage("c:\\datafile.mk",1)
vw = db.view("people")

class PatternFilter:
    def __init__(self, pattern, feld):
        self.feld = feld
        self.pattern = re.compile(pattern)

    def __call__(self, row):
        try:
            exec(self.feld+" = row."+self.feld)
        except AttributeError:
            return 0
        return self.pattern.search(eval(self.feld))is not None

    def union(feld_th, feld_na):
        c = feld_th[:]
        for i in range(len(feld_na)):
            if feld_na[i] not in feld_th:
                c.append(feld_na[i])
        return c

feld_th = "Themenbereiche" 
vf = vw.filter(PatternFilter("do.*", feld_th))

feld_na = "Nachname"
vf = vw.filter(PatternFilter("im.*", feld_na))
    
print feld_th, feld_na, union1(feld_th, feld_na)
print feld_th, feld_na, union2(feld_th, feld_na)

Wiebke