我有以下带有"problem_definition"列的示例数据帧:
ID problem_definition
1 cat, dog fish
2 turtle; cat; fish fish
3 hello book fish
4 dog hello fish cat
我想用单词标记"problem_definition"列。
以下是我的代码:
from nltk.tokenize import sent_tokenize, word_tokenize
import pandas as pd
df = pd.read_csv('log_page_nlp_subset.csv')
df['problem_definition_tokenized'] = df['problem_definition'].apply(word_tokenize)
上面的代码给了我以下错误:
TypeError:应为字符串或字节,如对象
实际的df['TEXT']
中可能有一个非字符串类对象(如NaN
(,但在您发布的数据中没有显示。
以下是如何找到有问题的值:
mask = [isinstance(item, (str, bytes)) for item in df['TEXT']]
print(df.loc[~mask])
如果你想删除这些行,你可以使用
df = df.loc[mask]
或者,正如PineNuts0所指出的,可以使用将整个列强制为str
数据类型
df['TEXT'] = df['TEXT'].astype(str)
例如,如果df['TEXT']
、中存在NaN值
import pandas as pd
from nltk.tokenize import sent_tokenize, word_tokenize
df = pd.DataFrame({'ID': [1, 2, 3, 4],
'TEXT': ['cat, dog fish',
'turtle; cat; fish fish',
'hello book fish',
np.nan]})
# ID TEXT
# 0 1 cat, dog fish
# 1 2 turtle; cat; fish fish
# 2 3 hello book fish
# 3 4 NaN
# df['TEXT'].apply(word_tokenize)
# TypeError: expected string or buffer
mask = [isinstance(item, (str, bytes)) for item in df['TEXT']]
df = df.loc[mask]
# ID TEXT
# 0 1 cat, dog fish
# 1 2 turtle; cat; fish fish
# 2 3 hello book fish
现在应用word_tokenize
的作品:
In [108]: df['TEXT'].apply(word_tokenize)
Out[108]:
0 [cat, ,, dog, fish]
1 [turtle, ;, cat, ;, fish, fish]
2 [hello, book, fish]
Name: TEXT, dtype: object
在apply
:中使用lambda
df = pd.DataFrame({'TEXT':['cat, dog fish', 'turtle; cat; fish fish', 'hello book fish', 'dog hello fish cat']})
df
TEXT
0 cat, dog fish
1 turtle; cat; fish fish
2 hello book fish
3 dog hello fish cat
df.TEXT.apply(lambda x: word_tokenize(x))
0 [cat, ,, dog, fish]
1 [turtle, ;, cat, ;, fish, fish]
2 [hello, book, fish]
3 [dog, hello, fish, cat]
Name: TEXT, dtype: object
如果您还需要转义标点符号,请使用:
df.TEXT.apply(lambda x: RegexpTokenizer(r'w+').tokenize(x))
0 [cat, dog, fish]
1 [turtle, cat, fish, fish]
2 [hello, book, fish]
3 [dog, hello, fish, cat]
Name: TEXT, dtype: object