Python 在Pandas中,如何获取包含列表的序列的值_counts()
我有一个Python 在Pandas中,如何获取包含列表的序列的值_counts(),python,pandas,Python,Pandas,我有一个pandas系列df.files,看起来像这样: In [79]: df.files Out[79]: 0 [{'url': 'http://www.apkmirror.com/wp-content/... 1 [{'url': 'http://www.apkmirror.com/wp-content/... 2 [{'url': 'http://www.apkmirror.com/wp-content/... 3 [{'url':
pandas
系列df.files
,看起来像这样:
In [79]: df.files
Out[79]:
0 [{'url': 'http://www.apkmirror.com/wp-content/...
1 [{'url': 'http://www.apkmirror.com/wp-content/...
2 [{'url': 'http://www.apkmirror.com/wp-content/...
3 [{'url': 'http://www.apkmirror.com/wp-content/...
4 [{'url': 'http://www.apkmirror.com/wp-content/...
5 [{'url': 'http://www.apkmirror.com/wp-content/...
6 [{'url': 'http://www.apkmirror.com/wp-content/...
7 [{'url': 'http://www.apkmirror.com/wp-content/...
8 [{'url': 'http://www.apkmirror.com/wp-content/...
9 [{'url': 'http://www.apkmirror.com/wp-content/...
10 [{'url': 'http://www.apkmirror.com/wp-content/...
11 [{'url': 'http://www.apkmirror.com/wp-content/...
12 [{'url': 'http://www.apkmirror.com/wp-content/...
13 [{'url': 'http://www.apkmirror.com/wp-content/...
14 [{'url': 'http://www.apkmirror.com/wp-content/...
15 [{'url': 'http://www.apkmirror.com/wp-content/...
16 [{'url': 'http://www.apkmirror.com/wp-content/...
17 [{'url': 'http://www.apkmirror.com/wp-content/...
18 [{'url': 'http://www.apkmirror.com/wp-content/...
19 [{'url': 'http://www.apkmirror.com/wp-content/...
20 [{'url': 'http://www.apkmirror.com/wp-content/...
21 [{'url': 'http://www.apkmirror.com/wp-content/...
22 [{'url': 'http://www.apkmirror.com/wp-content/...
23 [{'url': 'http://www.apkmirror.com/wp-content/...
24 [{'url': 'http://www.apkmirror.com/wp-content/...
25 [{'url': 'http://www.apkmirror.com/wp-content/...
26 [{'url': 'http://www.apkmirror.com/wp-content/...
27 [{'url': 'http://www.apkmirror.com/wp-content/...
28 [{'url': 'http://www.apkmirror.com/wp-content/...
29 [{'url': 'http://www.apkmirror.com/wp-content/...
...
16487 [{'url': 'http://www.apkmirror.com/wp-content/...
16488 []
16489 [{'url': 'http://www.apkmirror.com/wp-content/...
16490 [{'url': 'http://www.apkmirror.com/wp-content/...
16491 []
16492 [{'url': 'http://www.apkmirror.com/wp-content/...
16493 [{'url': 'http://www.apkmirror.com/wp-content/...
16494 [{'url': 'http://www.apkmirror.com/wp-content/...
16495 []
16496 []
16497 []
16498 [{'url': 'http://www.apkmirror.com/wp-content/...
16499 [{'url': 'http://www.apkmirror.com/wp-content/...
16500 [{'url': 'http://www.apkmirror.com/wp-content/...
16501 [{'url': 'http://www.apkmirror.com/wp-content/...
16502 [{'url': 'http://www.apkmirror.com/wp-content/...
16503 []
16504 []
16505 []
16506 []
16507 []
16508 []
16509 []
16510 []
16511 []
16512 []
16513 []
16514 []
16515 []
16516 []
一些值是空列表,而其他值是包含一个字典的列表,格式类似于以下内容:
In [80]: df.files.loc[0]
Out[80]:
[{'checksum': '9f6075f4c561792e48354277b46a6810',
'path': 'full/80832b9fca82ce0f58f4d23c511e5a1d657c40e8.php?id=2968',
'url': 'http://www.apkmirror.com/wp-content/themes/APKMirror/download.php?id=2968'}]
我想知道
df.files
中有多少条目实际上是空列表。但是,如果我尝试df.files.value\u counts()
,我会得到一个TypeError:unhabable type:'list'
。我该如何解决这个问题呢?如果需要,您可以先转换为元组
:
但如果只需要空列表的长度
用于计数列表
,则求和
布尔掩码的所有为真
s:
l = (df['files'].str.len() == 0).sum()
如果没有NaN
s值,则可以使用:
如果要查找空列表,为什么要使用值计数
len([i for i in df.files if len(i) == 0])
您也可以编写for循环来遍历列表:
for i in df.files:
count = 0
if len(i) == 0:
count = count + 1
else:
pass
或者(df['files'].apply(len)==0.sum()
(可能更快)@你说得对。以前从没用过。现在我定义了。willhm,df['files'].str.len()
可能更快(见其他答案)
len([i for i in df.files if len(i) == 0])
for i in df.files:
count = 0
if len(i) == 0:
count = count + 1
else:
pass