[python3]migrate dir_bcast_test and fdb scripts to python3

[ZhaohuiS]

Description of PR

Summary:
migrate the following scripts to python3, this PR can't be merged until #5534 is merged which has dependency of ptf_runner.py

ansible/roles/test/files/ptftests/dir_bcast_test.py
ansible/roles/test/files/ptftests/fdb.py
ansible/roles/test/files/ptftests/fdb_mac_expire_test.py
ansible/roles/test/files/ptftests/fdb_test.py

Signed-off-by: Zhaohui Sun zhaohuisun@microsoft.com

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 201911
• 202012

Approach

What is the motivation for this PR?

migrate dir_bcast_test and fdb scripts to python3

How did you do it?

Update test cases accordingly.

tests/fdb/test_fdb_mac_expire.py
tests/ipfwd/test_dir_bcast.py

How did you verify/test it?

run tests/fdb/test_fdb_mac_expire.py and tests/ipfwd/test_dir_bcast.py

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[lgtm-com]

This pull request introduces 1 alert when merging e158572 into 3212c2f - view on LGTM.com

new alerts:

• 1 for Wrong name for an argument in a call

[ZhaohuiS]

/azp run

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Azure Pipelines successfully started running 1 pipeline(s).

[ZhaohuiS]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).