Function has_sunken_brackets

IPython/core/inputtransformer2.py:646–656

Check if the depth of brackets in the list of tokens drops below 0

(tokens: List[tokenize.TokenInfo])

def has_sunken_brackets(tokens: List[tokenize.TokenInfo]):
    """Check if the depth of brackets in the list of tokens drops below 0"""
    parenlev = 0
    for token in tokens:
        if token.string in {"(", "[", "{"}:
            parenlev += 1
        elif token.string in {")", "]", "}"}:
            parenlev -= 1
            if parenlev < 0:
                return True
    return False

# Arbitrary limit to prevent getting stuck in infinite loops
TRANSFORM_LOOP_LIMIT = 500