>AttributeError：“list”对象没有属性“lower”（在小写数据框中）答案

【问题标题】：>AttributeError: 'list' object has no attribute 'lower' (in a lowercase dataframe)>AttributeError：“list”对象没有属性“lower”（在小写数据框中）
【发布时间】：2019-11-03 02:21:53
【问题描述】：

我不明白这个错误...在将其转换为列表之前，我已经将 df 转换为小写

数据框：

    all_cols
0   who is your hero and why
1   what do you do to relax
2   this is a hero
4   how many hours of sleep do you get a night
5   describe the last time you were relax

代码：

from sklearn.cluster import MeanShift
from sklearn.pipeline import Pipeline
from sklearn.preprocessing import FunctionTransformer
from sklearn.feature_extraction.text import TfidfVectorizer

df['all_cols'] = df['all_cols'].str.lower()
df_list = df.values.tolist()

pipeline = Pipeline(steps=[
('tfidf', TfidfVectorizer()),
('trans', FunctionTransformer(lambda x: x.todense(), accept_sparse=True)),
('clust', MeanShift())])

pipeline.fit(df_list)
pipeline.named_steps['clust'].labels_

result = [(label,doc) for doc,label in zip(df_list, pipeline.named_steps['clust'].labels_)]

for label,doc in sorted(result):
    print(label, doc)

但我在这一行有一个错误：

AttributeError Traceback（最近一次调用最后一次）在

----> 1 个 pipeline.fit(df_list)
 2 pipeline.named_steps['clust'].labels_
AttributeError: 'list' 对象没有属性 'lower'

但是如果我之前已经传递了小写数据框，为什么程序会返回小写错误？

【问题讨论】：

你确定所有行都是字符串而不是列表吗？

标签： python pandas cluster-analysis lowercase

【解决方案1】：

把它转换成pandas数据框，然后做你上面做的操作。它会起作用的。我还贴了sn-p，你可以自己试试。

import pandas as pd

col = pd.Series(["who is your hero and why", "what do you do to relax", "this is a hero", "how many hours of sleep do you get a night", "describe the last time you were relax"])
fr = {"all_cols":col}
df = pd.DataFrame(fr)
df['all_cols'] = df['all_cols'].str.lower()
df_list = df.values.tolist()

【讨论】：

【解决方案2】：

为df_list 指定列以避免嵌套列表：

df_list = df.values.tolist()
print (df_list)
[['who is your hero and why'], 
 ['what do you do to relax'], 
 ['this is a hero'], 
 ['how many hours of sleep do you get a night'], 
 ['describe the last time you were relax']]

df_list = df['all_cols'].values.tolist()
print (df_list)
['who is your hero and why', 
 'what do you do to relax', 
 'this is a hero',
 'how many hours of sleep do you get a night',
 'describe the last time you were relax']

【讨论】：