=== Bracket/paren depth tracking === Colon in key: expr=d['b:c'], value=2 Slice colon: expr=items[1:3], value=[20, 30] Function call: expr=pair(1, 2), value=(1, 2) Default arg colon: expr=pair(3), value=(3, ':') Nested brackets: expr=matrix[0][1], value=2 === Inline template literal tests === Empty nested: Template With content: Template Concatenation: Template Mixed quotes: Template Nested interp: Template === Backslashes not allowed in expressions (PEP 498/750) === Backslash in expression: SyntaxError Escaped newline: SyntaxError === Format spec with special characters ===