我有一个Spark Dataframe,每行都有一个评论。
+--------------------+
| reviewText|
+--------------------+
|Spiritually and m...|
|This is one my mu...|
|This book provide...|
|I first read THE ...|
+--------------------+
我试过了:
SplitSentences = df.withColumn("split_sent",sentencesplit_udf(col('reviewText')))
SplitSentences = SplitSentences.select(SplitSentences.split_sent)
然后我创建了函数:
def word_count(text):
return len(text.split())
wordcount_udf = udf(lambda x: word_count(x))
df2 = SplitSentences.withColumn("word_count",
wordcount_udf(col('split_sent')).cast(IntegerType())
我想计算每个评论(行)中每个句子的单词,但它不起作用。
答案 0 :(得分:4)
您可以使用split
内置函数来分割句子并使用size
内置函数将数组长度计为< / p>
df.withColumn("word_count", F.size(F.split(df['reviewText'], ' '))).show(truncate=False)
这样你就不会需要昂贵的udf功能
举个例子,假设你有一个句子数据框
+-----------------------------+
|reviewText |
+-----------------------------+
|this is text testing spliting|
+-----------------------------+
应用上述size
和split
功能后,您应该
+-----------------------------+----------+
|reviewText |word_count|
+-----------------------------+----------+
|this is text testing spliting|5 |
+-----------------------------+----------+
如果您在一行中有多个句子,如下所示
+----------------------------------------------------------------------------------+
|reviewText |
+----------------------------------------------------------------------------------+
|this is text testing spliting. this is second sentence. And this is the third one.|
+----------------------------------------------------------------------------------+
然后你必须写一个udf
函数,如下所示
from pyspark.sql import functions as F
def countWordsInEachSentences(array):
return [len(x.split()) for x in array]
countWordsSentences = F.udf(lambda x: countWordsInEachSentences(x.split('. ')))
df.withColumn("word_count", countWordsSentences(df['reviewText'])).show(truncate=False)
应该给你
+----------------------------------------------------------------------------------+----------+
|reviewText |word_count|
+----------------------------------------------------------------------------------+----------+
|this is text testing spliting. this is second sentence. And this is the third one.|[5, 4, 6] |
+----------------------------------------------------------------------------------+----------+
我希望答案很有帮助