python: `pylint` check found many error

**Bug Description**
There are many error about `pylint`, and the pr of [feat: support pylint check in github action](https://github.com/4paradigm/OpenMLDB/pull/1873) has already integrate pylint to GitHub actions, So it is time to solve those error.

**Expected Behavior**
Execute `make lint` and got no errors.

**Steps to Reproduce**

1. execute command of `make lint`

And I'd like to solve this issue.

Run `make lint` to see the pylint errors. Look at the GitHub Actions configuration from PR #1873 to understand the linting setup. Fix the errors in the Python codebase, likely in scripts or tools directories. Verify by running the lint command again to ensure no errors remain.

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