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

Solution:
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

solution:
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.)