move {{ and }} matching so that it gets highlighted correctly

Author: lilydjwg

syntax/python.vim

@@ -252,9 +252,9 @@ if s:Enabled('g:python_highlight_string_format')
     syn match pythonStrFormat '{{\|}}' contained containedin=pythonString,pythonUniString,pythonUniRawString,pythonRawString
     syn match pythonStrFormat '{\%(\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\d\+\)\=\%(\.\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\[\%(\d\+\|[^!:\}]\+\)\]\)*\%(![rsa]\)\=\%(:\%({\%(\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\d\+\)}\|\%([^}]\=[<>=^]\)\=[ +-]\=#\=0\=\d*,\=\%(\.\d\+\)\=[bcdeEfFgGnosxX%]\=\)\=\)\=}' contained containedin=pythonString,pythonUniString,pythonUniRawString,pythonRawString
   else
-    syn match pythonStrFormat "{{\|}}" contained containedin=pythonString,pythonRawString,pythonFString,pythonRawFString
     syn match pythonStrFormat "{\%(\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\d\+\)\=\%(\.\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\[\%(\d\+\|[^!:\}]\+\)\]\)*\%(![rsa]\)\=\%(:\%({\%(\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\d\+\)}\|\%([^}]\=[<>=^]\)\=[ +-]\=#\=0\=\d*,\=\%(\.\d\+\)\=[bcdeEfFgGnosxX%]\=\)\=\)\=}" contained containedin=pythonString,pythonRawString
-    syn region pythonStrInterpRegion start="{"he=e+1,rs=e+1 end="\%(![rsa]\)\=\%(:\%({\%(\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\d\+\)}\|\%([^}]\=[<>=^]\)\=[ +-]\=#\=0\=\d*,\=\%(\.\d\+\)\=[bcdeEfFgGnosxX%]\=\)\=\)\=}"hs=s-1,re=s-1 extend contained containedin=pythonFString,pythonRawFString contains=pythonStrInterpRegion,@pythonExpression
+    syn region pythonStrInterpRegion start="{"he=e+1,rs=e+1 end="\%(![rsa]\)\=\%(:\%({\%(\%([^[:cntrl:][:space:][:punct:][:digit:]]\|_\)\%([^[:cntrl:][:punct:][:space:]]\|_\)*\|\d\+\)}\|\%([^}]\=[<>=^]\)\=[ +-]\=#\=0\=\d*,\=\%(\.\d\+\)\=[bcdeEfFgGnosxX%]\=\)\=\)\=}"hs=s-1,re=s-1 extend contained containedin=pythonFString contains=pythonStrInterpRegion,@pythonExpression
+    syn match pythonStrFormat "{{\|}}" contained containedin=pythonString,pythonRawString,pythonFString,pythonRawFString
   endif
 endif
 

tests/test.py

@@ -235,6 +235,7 @@ async def Test
 f"{var}...{arr[123]} normal {var['{'] // 0xff} \"xzcb\" 'xzcb' {var['}'] + 1} text"
 f"{expr1 if True or False else expr2} wow {','.join(c.lower() for c in 'asdf')}"
 f"hello {expr:.2f} yes {(lambda: 0b1)():#03x} lol {var!r}"
+f'brackets: {{ 1 + 2 }} and {{{{ 3 + 4 }}}}'
 
 # Doctests.