## Docstrings

You are using comments instead of docstrings, which is not a good tone, as I think. You can read more about docstring in [PEP 257](https://www.python.org/dev/peps/pep-0257/). Also it's not necessary to write class name in docstring. For example, you can write `Implements the operations in Red Black Tree` instead of `class RedBlackTree implements the operations in Red Black Tree`.

## Type hinting

Your code doesn't have type hinting at all. It's not really a bad thing, but it's always better to do type hinting. You can read more about why you may want to do it in [PEP 484](https://www.python.org/dev/peps/pep-0484/) and how to do it [here](https://docs.python.org/3/library/typing.html).

## Double underscores in method names

It's not really necessary to write `__` before the method name, because `_` is already enough. But it's a matter of preference.

## Node colors

I'd use [enum](https://docs.python.org/3/library/enum.html) instead of 0/1 for colors. Your code will be more understandable if you write `self.color = Color.Red` instead of `self.color = 1`.

## Node.data

Data is very wide and uninformative name. If `data` holds `key`, why don't you name it `key`?

## sys.stdout

I suppose that there's no need to overcomplicate your code by using `sys.stdout.write` instead of `print`, which also prints to stdout.

## RedBlackTree.pretty_print()

You should definitely read about [dunders](https://holycoders.com/python-dunder-special-methods/). They will allow you to integrate your class with default python methods. In this particular case dunders will allow you to use `print(some_tree)` instead of `some_tree.pretty_print()`.

## Long methods

Some of your methods are really long and difficult to read. For example, `__fix_delete`. Also comments like `# case 3.1` are uninformative. I guess you should extract each case in separate function and write a little bit more about each case in docstrings.

## Style comments

I think that every Python programmer should use [pylint](https://pylint.org/). It's a good tool to find small issues like too long lines, absence of spaces after commas, etc. It's really helpful, but try not to become pylint maniac - it's not always necessary to achieve 10/10.