python出现TypeError: sequence item 1: expected string or Unicode, int found

本文解决在使用Python进行Spark编程时遇到的TypeError问题,详细解析错误原因,并提供代码修改方案,确保输出时正确处理数据类型。

1、当运行python出现TypeError: sequence item 1: expected string or Unicode, int found,如下错误信息:

org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "/usr/local/src/spark-1.6.3-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/worker.py", line 111, in main
    process()
  File "/usr/local/src/spark-1.6.3-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/worker.py", line 106, in process
    serializer.dump_stream(func(split_index, iterator), outfile)
  File "/usr/local/src/spark-1.6.3-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/serializers.py", line 133, in dump_stream
    for obj in iterator:
  File "/usr/local/src/spark-1.6.3-bin-hadoop2.6/python/lib/pyspark.zip/pyspark/rdd.py", line 1494, in func
  File "/sunxj/spark/pyspark/wordcount_1.py", line 18, in <lambda>
    result = rdd.flatMap(f).map(lambda word:(word,1)).reduceByKey(lambda a,b:a+b).sortBy(lambda x:x[1],ascending=False).map(lambda x:'\t'.join([x[0],x[1]]))
TypeError: sequence item 1: expected string or Unicode, int found

	at org.apache.spark.api.python.PythonRunner$$anon$1.read(PythonRDD.scala:166)
	at org.apache.spark.api.python.PythonRunner$$anon$1.<init>(PythonRDD.scala:207)
	at org.apache.spark.api.python.PythonRunner.compute(PythonRDD.scala:125)
	at org.apache.spark.api.python.PythonRDD.compute(PythonRDD.scala:70)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:270)
	at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:270)
	at org.apache.spark.rdd.MapPartitionsRDD.compute(MapPartitionsRDD.scala:38)
	at org.apache.spark.rdd.RDD.computeOrReadCheckpoint(RDD.scala:306)
	at org.apache.spark.rdd.RDD.iterator(RDD.scala:270)
	at org.apache.spark.scheduler.ResultTask.runTask(ResultTask.scala:66)
	at org.apache.spark.scheduler.Task.run(Task.scala:89)
	at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:227)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

如下图所示:

2、出现此错误表示在输出时,不能以int方式进行join,如下代码x[1]是一个数字:

3、只需要将x[1]通过str转换成字符串即可,如下图所示:

 

你遇到的错误: ``` TypeError: sequence item 1: expected str instance, dict found ``` 表示你尝试使用字符串的 `join()` 方法去拼接一个**包含字典(dict)的列表**,而 `join()` 方法只接受字符串类型的元素。 --- ### ❌ 错误示例: ```python data = ["line1", {"key": "value"}, "line3"] result = "\n".join(data) ``` 这会报错: ``` TypeError: sequence item 1: expected str instance, dict found ``` 因为 `data` 列表中的第 2 个元素是一个字典,而不是字符串。 --- ### ✅ 正确做法:确保列表中所有元素都是字符串 #### ✅ 方法一:先将所有元素转为字符串 ```python data = ["line1", {"key": "value"}, "line3"] str_data = [str(item) for item in data] result = "\n".join(str_data) print(result) ``` 输出: ``` line1 {'key': 'value'} line3 ``` --- #### ✅ 方法二:只保留字符串元素 ```python data = ["line1", {"key": "value"}, "line3"] str_data = [item for item in data if isinstance(item, str)] result = "\n".join(str_data) print(result) ``` 输出: ``` line1 line3 ``` --- #### ✅ 方法三:自定义转换逻辑(如提取字典内容) 如果你知道字典的结构,可以提取特定字段: ```python data = ["line1", {"text": "important"}, "line3"] str_data = [item['text'] if isinstance(item, dict) else item for item in data] result = "\n".join(str_data) print(result) ``` 输出: ``` line1 important line3 ``` --- ### ✅ 总结 - `'\n'.join()` 要求列表中所有元素都必须是 `str` 类型 - 如果列表中包含 `dict`、`int`、`None` 等非字符串类型,必须先进行转换或过滤 - 可以使用 `isinstance()` 判断类型,或用 `str()` 强制转换 --- ###
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