TypeError: 'generator' object has no attribute '__getitem__'

MAS picture MAS · Jun 15, 2015 · Viewed 49.1k times · Source

I have written a generating function that should return a dictionary. however when I try to print a field I get the following error

print row2['SearchDate']
TypeError: 'generator' object has no attribute '__getitem__'

This is my code

from csv import DictReader
import pandas as pd
import numpy as np


def genSearch(SearchInfo):
    for row2 in DictReader(open(SearchInfo)):
        yield row2

train = 'minitrain.csv'

SearchInfo = 'SearchInfo.csv'

row2 = {'SearchID': -1}

for row1 in DictReader(open(train)):
    if 'SearchID' in row1 and 'SearchID' in row2 and row1['SearchID'] == row2['SearchID']:
        x = deepcopy( row1 )
        #x['SearchDate'] = row2['percent']
        x.update(row2)    
        print 'new'
        print x
    else: 
        #call your generator
        row2 = genSearch(SearchInfo)
        print row2['SearchDate']

Answer

hspandher picture hspandher · Jun 15, 2015

Generator returns an iterator, you explicitly needs to call next on it.

Your last line of code should be something like -

rows_generator = genSearch(SearchInfo)
row2 = next(rows_generator, None)
print row2['SearchDate']

Ideally, we use iterators in a loop, which automatically does the same for us.