我已经阅读了python文档中的示例,但仍然无法弄清楚这个方法的含义.有人可以帮忙吗?以下是python文档中的两个示例
>>> from collections import defaultdict
>>> s = 'mississippi'
>>> d = defaultdict(int)
>>> for k in s:
... d[k] += 1
...
>>> d.items()
[('i', 4), ('p', 2), ('s', 4), ('m', 1)]
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和
>>> s = [('yellow', 1), ('blue', 2), ('yellow', 3), ('blue', 4), ('red', 1)]
>>> d = defaultdict(list)
>>> for k, v in s:
... d[k].append(v)
...
>>> d.items()
[('blue', [2, 4]), ('red', [1]), ('yellow', [1, 3])]
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参数int和list用于什么?
我有这个代码,在我的json文件中为用户添加了50个点,但是'dict' object has no attribute 'append'在尝试将新用户添加到用户时我不断得到:
def updateUsers(chan):
j = urllib2.urlopen('http://tmi.twitch.tv/group/user/' + chan + '/chatters')
j_obj = json.load(j)
with open('dat.dat', 'r') as data_file:
data = json.load(data_file)
for dat in data['users']:
if dat in j_obj['chatters']['moderators'] or j_obj['chatters']['viewers']:
data['users']['tryhard_cupcake']['Points'] += 50
else:
data['users'].append([dat]) # append doesn't work here
with open('dat.dat', 'w') as out_file:
json.dump(data, out_file)
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添加新对象/用户的正确方法是users什么?