Hadoop reports an error. Cannot access scala.serializable and python MapReduce reports an error

Record the problems encountered when doing school Hadoop homework. The homework is more basic, that is, calling Hadoop through makefile to execute the MapReduce program written in advance

Error 1

An error occurred in the Hadoop wordcount code

java: cannot access scala.Serializable class file for scala.Serializable not found

An error is reported

through this Q & A on stack overflow, I guess that the scala version is incompatible with the Hadoop version, so rollback to 2.7 will solve the problem

Error report 2

Attempting to run Python on Hadoop. But an error is reported. The error information is not detailed:
insert a picture description here

add the following at the beginning of the source code:

#!/usr/bin/env python
# -*-coding:utf-8 -*

(the problem with the coding format is really that I don’t know how to debug it.)

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