引发异常后继续执行循环

Question

for item in r.get_iterator():
    if 'retweeted_status' in item:
        print('aa')
    else:
        id_twitty = item['id']
        count_ret = item['retweet_count']

如果item['id']抛出KeyError异常，则执行终止。

如何使for循环在异常后继续执行？

Answer 1

您可以尝试捕获引发的KeyError异常，然后将其丢弃：

for item in r.get_iterator():
    if 'retweeted_status' in item:
        print('aa')
    else:
        try:
            id_twitty = item['id']
            count_ret = item['retweet_count']
        except KeyError:
            pass

Answer 2

对于EAFP样式，您可以应用LBYL ，如果在item找不到id ，则使用continue ：

for item in r.get_iterator():
    if 'retweeted_status' in item:
        print('aa')
    elif 'id' not in item:
        continue
    else:
        id_twitty = item['id']
        count_ret = item['retweet_count']

Answer 3

您可以先检查item['id']存在：

for item in r.get_iterator():
    if 'retweeted_status' in item:
        print('aa')
    else:
        if 'id' in item:
            id_twitty = item['id']
            count_ret = item['retweet_count']

如果不存在，则使用None ：

for item in r.get_iterator():
    if 'retweeted_status' in item:
        print('aa')
    else:
        id_twitty = item.get('id')
        count_ret = item['retweet_count']

如果不存在，请使用其他一些默认值：

default_id = 0

for item in r.get_iterator():
    if 'retweeted_status' in item:
        print('aa')
    else:
        id_twitty = item.get('id', default_id)
        count_ret = item['retweet_count']

Answer 4

for item in r.get_iterator():
    if 'retweeted_status' in item:
        print('aa')
    else:
        id_twitty = item.get('id', None)
        count_ret = item.get('retweet_count', None)
        if not id_twitty or not count_ret:
            print "could not retrieve id or count"
            # handle error here