Redundant parentheses around string/int literals

[wimglenn]

Black could remove redundant parens from keyword arguments
Playground link here

Blackened style

foo(x=("hello"))
foo(x=(1))

Desired style

foo(x="hello")
foo(x=1)

I get this a lot when black has reformatted a multi line string which was using implicit concatenation all onto one line. It doesn't actually join the strings (OK, I understand the reason for that) but when you manually delete quotes to join them yourself, you are gonna get redundant parens hanging around.

[JelleZijlstra]

I tried doing this before the last release but unfortunately it caused some issues, so I had to revert. See #1079.

[astier]

Can confirm. Would be really helpful.

[bbugyi200]

#1132 fixes this for strings, but not the foo(x=(1)) case.

[ichard26]

Another example (from #1151, a duplicate of this issue):

foo(a=1, **{"b": 2} if bar() else {}, c=3)
foo(a=1, **({"b": 2} if bar() else {}), c=3)

[Akuli]

Not fixed for strings yet #2307 assert foo == ("Blah blah blah. Blah.")

[bbugyi200]

Not fixed for strings yet #2307 assert foo == ("Blah blah blah. Blah.")

@Akuli This was fixed by #1132, but this PR has been masked with a feature flag (--experimental-string-processing):

Note that there is an effort to eventually enable this feature by default (see #2188) once all of the kinks have been worked out.