import gitlab.exceptions

# of course gitlab connection is set and auth() without problems
# connection is set not to use SSL and to use token - root almighty token
gitlab_projects = gitlab.projects.list(search="test_project_1")
project = gitlab_projects[0]  # I know for certain there is only one project

project_branches = project.branches.list()
for project_branch in project_branches:
    print("Setting protection for branch {}".format(branch_name))
    try:
        project_branch.protect(
            developers_can_push=False,
            developers_can_merge=False
        )
    except gitlab.exceptions.GitlabProtectError as e:
        print("Exception caught while setting protection "
                "for branch {} -> {} -> branch protection skipped, rest "
                "will proceed as usual"
                .format(branch_name, e.__str__()))

Setting protection for branch strange/stranger
Exception caught while setting protection for branch strange/stranger -> 404: b'{"error":"404 Not Found"}' -> branch protection skipped, rest will proceed as usual

Setting protection for branch strange/stranger
Traceback (most recent call last):
  File "/home/kduchno/Envs/pythoning/lib/python3.6/site-packages/gitlab/exceptions.py", line 251, in wrapped_f
    return f(*args, **kwargs)
  File "/home/kduchno/Envs/pythoning/lib/python3.6/site-packages/gitlab/v4/objects.py", line 874, in protect
    self.manager.gitlab.http_put(path, post_data=post_data, **kwargs)
  File "/home/kduchno/Envs/pythoning/lib/python3.6/site-packages/gitlab/__init__.py", line 827, in http_put
    post_data=post_data, **kwargs)
  File "/home/kduchno/Envs/pythoning/lib/python3.6/site-packages/gitlab/__init__.py", line 706, in http_request
    response_body=result.content)
gitlab.exceptions.GitlabHttpError: 404: b'{"error":"404 Not Found"}'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "main.py", line 155, in <module>
    __create_additional_branches_in_project(project)
  File "main.py", line 123, in __create_additional_branches_in_project
    __setup_branch_protection_in_project(project, branches)
  File "main.py", line 81, in __setup_branch_protection_in_project
    developers_can_merge=dev_merge
  File "/home/kduchno/Envs/pythoning/lib/python3.6/site-packages/gitlab/cli.py", line 42, in wrapped_f
    return f(*args, **kwargs)
  File "/home/kduchno/Envs/pythoning/lib/python3.6/site-packages/gitlab/exceptions.py", line 253, in wrapped_f
    raise error(e.error_message, e.response_code, e.response_body)
gitlab.exceptions.GitlabProtectError: 404: b'{"error":"404 Not Found"}'