ec2 python version change

[ec2-user@ip-172-31-7-149 lambda]$ python --version
Python 2.7.16

[ec2-user@ip-172-31-7-149 lambda]$ sudo yum list | grep python3

[ec2-user@ip-172-31-7-149 lambda]$ sudo yum install python3 python3-pip

[ec2-user@ip-172-31-7-149 lambda]$ sudo python --version
Python 2.7.16
[ec2-user@ip-172-31-7-149 lambda]$ alias python=python3
[ec2-user@ip-172-31-7-149 lambda]$ python --version
Python 3.7.4