What regex will capture multiple instances inside braces/parentheses?

Question

How do I use regex to capture, say, every run of space characters \ + inside brackets? For example, in the string, "abc and 123 {foo-bar bar baz } bit {yummi tummie} byte." I should find four matches inside {} -- but nothing else. Assume Python language and that the string content is unknown.

EDIT: Also assume that there are NO nested braces.

Answer 1

A lookahead can check if there is a } ahead without any { in between.

\s+(?=[^{]*})

• \s is a short for whitespace character [ \t\r\n\f]. Match + one or more.

• (?=[^{]*}) looks ahead if there is a } with any non { in between.

Demo at regex101