Программа с использованием генератора синтаксических анализаторов TPG на основе синтаксических конструкций для типов данных

#!/usr/bin/python
# -*- coding: utf-8 -*-
 
import tpg
 
 
class unit:
    def __init__(self, cons, **attrs):
        self.cons = cons
        self.attrs = attrs.copy()
    def __str__(self):
        s = ""
        for k in self.attrs:
            s += ' ' + k + ' = ' + str(self.attrs[k])
        return self.cons + s
 
def printLst(list):
    print '[',
    for i in xrange(len(list)):
        if i < len(list)-1:
            print list[i], ',',
        else:
            print list[i],
    print ']'
 
def IsPeriodic(list):
    res = []
    for el in list:
        if (el.cons == 'Magazine' or el.cons =='Newspaper'):
            res.append(el)
    return res
 
def getByMonth(month,list):
    res = []
    for el in IsPeriodic(list):
        if el.attrs['month']==month:
            res.append(el)
    return res
 
def getByMonths(months,list):
    res = []
    for m in months:
        res = res + getByMonth(m,list)
    return res
 
def getAuthors(lst):
    res = []
    for el in lst:
        if (el.cons == 'Book'):
            res.append(el.attrs['author'])
    return list(set(res))
   
def getByTitle(title,list):
    return filter(lambda x:x.attrs['name'] == title, list)
 
class LibParser(tpg.Parser):
    r"""
    separator spaces: '\s+';
    token string: '".*?"' ; 
    token number: '\d+' int ;
    
    START/lib-> '\[' $lib = []$ (unit/u $lib.append(u)$ (',' unit/u $ lib.append(u)$)*)?'\]' ;
    unit/u ->  'Book'/c string/au string/n  $ u = unit(cons = c, author = au, name = n)$|
    'Newspaper'/c string/n number/d number/m number/y $u = unit(cons = c, name = n, day = d, month = m, year = y)$ | 
    'Magazine'/c string/n number/m number/y $u = unit(cons = c, name = n, month = m, year = y)$;
    """
    
library = '[Book "Tolstoy" "Voyna i mir" , Magazine "Esqire" 5 2005 , Magazine "Kommersant" 7 2005 , Book "Miller" "Tropik raka" , Newspaper "AiF" 12 04 2006, Book "Tolstoy" "Voskresenie"]'
L = LibParser()
g = L(library)
printLst(IsPeriodic(g))
printLst(getByTitle('"Kommersant"',g))
printLst(getByMonth(5, g))
printLst(getByMonths([4, 5], g))
printLst(getAuthors(g))