python - Searching for a sequence in a text -

i have run logic problem.

i have string declared follows:

fruits = "banana grapes apple" vegetables = "potatoes cucumber carrot" 

now there text sentences, , have search word in front of text format <vegetables> <fruits>

i ate carrot grapes ice cream dessert. 

answer : ate

dad , mom brought banana cucumber , milk. 

answer : brought

what thinking split sentence , put in array, , sequence, able break sentence matching sequence problem.

wd = sentence.split(' ') x in wd.strip().split(): # have sequence 

now, have text in front of text format

you're using wrong data-structures here, convert fruits , vegetables sets. problem easy solve:

>>> fruits = set("banana grapes apple".split()) >>> vegetables = set("potatoes cucumber carrot".split()) >>> fruits_vegs = fruits | vegetables                   >>> string import punctuation def solve(text):                                        spl = text.split()     #use itertools.izip , iterators memory efficiency.     x, y in zip(spl, spl[1:]):          #strip off punctuation marks         x,y = x.translate(none, punctuation), y.translate(none, punctuation)         if y in fruits_vegs , x not in fruits_vegs:             return x ...          >>> solve('i ate carrot grapes ice cream dessert.') 'ate' >>> solve('dad , mom brought banana cucumber , milk.') 'brought' >>> solve('banana cucumber , carrot.') 'and'