Even though the Jedi Council greatly disapproved of Anakin becoming a Jedi, Obi-Wan still took him under his wing after promising Qui-Gon Jinn. Anakin eventually becomes Darth Vader...
Has Obi-Wan ever expressed regret, either openly to someone or to himself, in teaching Anakin the ways of the Jedi?
I'm happy to accept any canon source (movies, novels etc.).
Disclaimer: I have seen the first 6 episodes a long time ago in a cinema far, far away.
Yes, when he talks to Luke in Return of the Jedi:
According to wikiquote the dialogue was:
Obi-wan: Luke, you're going to find that many of the truths we cling to depend greatly on our own point of view. Anakin was a good friend. When I first knew him, your father was already a great pilot. But I was amazed how strongly the Force was with him. I took it upon myself to train him as a Jedi. I thought that I could instruct him just as well as Yoda. I was wrong.
However, according to IMDB:
Obi-Wan: Luke, you're going to find that many of the truths we cling to depend greatly on our own point of view. What happened to your father was my fault... from a certain point of view. Anakin was a good friend. When I first met him, your father was already a great pilot. But I was amazed how strongly the Force was with him. I took it upon myself to train him as a Jedi. I thought that I could instruct him just as well as Yoda. I was wrong. During the Clone Wars, it wasn't long before the Emperor sensed Anakin's powers and lured him to the Dark Side.
This seems to be a version of the exchange that was in the 3rd Draft (also here as Revenge of the Jedi), which has a different version of the dialogue:
Obi-Wan: I don't blame you for being angry. If I was wrong in what I did, it certainly wouldn't have been for the first time. You see, what happened to your father was my fault.
[Pause]
Obi-Wan: Anakin was a good friend.
[Pause]
Obi-Wan: When I first knew him, your father was already a great pilot. But I was amazed how strongly the Force was with him. I took it upon myself to train him as a Jedi. I thought that I could instruct him just as well as Yoda. I was wrong. My pride has had terrible consequences for the galaxy.
In the novel Kenobi by John Jackson Miller, Obi-Wan has these thoughts about Anakin:
In the Prologue:
I still can't believe the Jedi Order is gone and the Republic, corrupted and in the hands of Palpatine. And Anakin, corrupted as well. The holovids I saw of him slaughtering the Jedi younglings in the Temple still haunt my dreams, and shatter my heart into pieces, over and over again.
In Chapter 13:
It's not like I'm going to suddenly get my friends back. It's not like I'm going to feel any better about what I had to do to poor Anakin. It's not like..
In Chapter 40:
Anakin had flaws of his own. Flaws I failed to see, that I didn't prepare him to deal with. But the Emperor played a role. I don't know if it would have been possible to isolate Anakin from his influence. I tried, but too late.
