get方法返回的是一个列表吗？

[EastonLiu]

今天在看python基础教程，对于书中这个函数不是很明白
def init(data):
data['first']={}
data['middle']={}
data['last']={}
def lookup(data,label,name):
return data[label].get(name)
def store(data,full_name):
names=full_name.split()
if len(names)==2:
names.insert(1,'')
labels='first','middle','last'
for label,name in zip(labels,names):
people=lookup(data,label,name)
if people:
people.append(full_name)
else:
data[label][name]=full_name
people=lookup(data,label,name) 返回的是一个值，怎么能用people.append(full_name)呢？append是列表的方法啊 。

[oyljerry]

people=lookup(data,label,name) 返回的并不一定是值，它是返回的字典的值，它也可能是list，所以可以append，你可以看看people具体的类型

[EastonLiu]

以下是调用函数： >>> mynames={} >>> init(mynames) >>> store(mynames,'aaa bbb ccc') >>> mynames {'first': {'aaa': 'aaa bbb ccc'}, 'middle': {'bbb': 'aaa bbb ccc'}, 'last': {'ccc': 'aaa bbb ccc'}} >>> lookup(mynames,'first','aaa') 'aaa bbb ccc' 在这里lookup返回的是一个字符串，用append方法就会报错 >>> store(mynames,'aaa bbb ddd') Traceback (most recent call last): File "<pyshell#120>", line 1, in <module> store(mynames,'aaa bbb ddd') File "C:\Users\907968\AppData\Local\Programs\Python\Python36\examples\1.py", line 15, in store people.append(full_name) AttributeError: 'str' object has no attribute 'append'

[EastonLiu]

引用 1 楼 oyljerry 的回复:

people=lookup(data,label,name) 返回的并不一定是值，它是返回的字典的值，它也可能是list，所以可以append，你可以看看people具体的类型

我试了下，字典返回的也不是list啊 以下是调用函数： >>> mynames={} >>> init(mynames) >>> store(mynames,'aaa bbb ccc') >>> mynames {'first': {'aaa': 'aaa bbb ccc'}, 'middle': {'bbb': 'aaa bbb ccc'}, 'last': {'ccc': 'aaa bbb ccc'}} >>> lookup(mynames,'first','aaa') 'aaa bbb ccc' 在这里lookup返回的是一个字符串，用append方法就会报错 >>> store(mynames,'aaa bbb ddd') Traceback (most recent call last): File "<pyshell#120>", line 1, in <module> store(mynames,'aaa bbb ddd') File "C:\Users\907968\AppData\Local\Programs\Python\Python36\examples\1.py", line 15, in store people.append(full_name) AttributeError: 'str' object has no attribute 'append'

[oyljerry]

那就错误提示你了，people是str类型不是list，所以不能用append，你书上的代码有问题