在 Python 中循环时更新列表时出错

import fitzdoc = fitz.open("cubeo/40337_02.pdf")page = doc[3]blocks = page.get_text("dict", flags = fitz.TEXTFLAGS_TEXT)["blocks"]for block in blocks:     entries = []    if len(block["lines"]) > 3: # ignora legendas e número de página        for line in block["lines"]:             spans = []            for span in line["spans"]:                spans.append({"text": span["text"].replace("�", " "), "size": int(span["size"]), "font": span["font"]})            # While there are spans left            while True:                # Delimits where an entry starts                entry_first_position = None                for i, span in enumerate(spans):                    if span["font"] == "Sb&cuSILCharis-Bold":                        entry_first_position = i                        break                if entry_first_position is not None:                    # Delimits where an entry ends                    entry_last_position = None                    for i, span in enumerate(spans[entry_first_position:], start=entry_first_position):                        if span["font"] == "Sb&cuSILCharis-Bold":                            entry_last_position = i                            break                    if entry_last_position is not None:                        # Whole entry is added as a list                        append_list = spans[entry_first_position:entry_last_position]                        entries.append(append_list)                        spans = spans[:entry_first_position] + spans[entry_last_position:]                    else:                        break                else:                    break             print(spans)

for i, span in enumerate(spans[entry_first_position:], start=entry_first_position):

for i, span in enumerate(spans[entry_first_position+1:], start=entry_first_position+1):