TypeError：'generator'對象沒有屬性'__getitem__'

Question

我寫了一個應該返回字典的生成函數。然而，當我嘗試打印領域，我得到以下錯誤

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

這是我的代碼

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 1

發電機返回一個迭代器，你需要明確未來調用就可以了。

你的代碼最後一行應該是這樣的 -

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

Answer 2

發電機必然迭代，不iterables。可計算元件包含 __item__()和__getitem__()方法，而迭代器包含next()/__next__()方法（Python版本2.x/3.x）。