As a guess I would suspect one of the two python specific plugins you mentioned (Jedi and Anaconda), just based on your mention of how the key doesn’t work in python files specifically. You could verify that by disabling both plugins and seeing if the problem goes away or not. If it does, enable them again one at a time to see if the problem recurs.
Something that can often be helpful in this case is sublime’s ability to log commands as they are executed. You can open the Sublime console via Ctrl+` or
View > Show Console and enter the command:
From that point forward (until you restart sublime or run the same command with
False), every time sublime executes a command, its name will be displayed in the console. If you press the key that’s giving you trouble, what it displays may point at the culprit.
For example, the
( key usually generates a command of
insert_snippet (if you have the appropriate option turned on), which causes it to insert both parts of the pair for you at once. If you use the Jedi autocompletion package, the same key executes the command