无法循环访问QTableWidget的列

table_widget = QTableWidget()  # 创建QTableWidget对象

# 获取列数
column_count = table_widget.columnCount()

# 遍历列
for column_index in range(column_count):
    # 通过列索引获取表格单元格数据
    for row_index in range(table_widget.rowCount()):
        cell_item = table_widget.item(row_index, column_index)
        if cell_item is not None:
            cell_data = cell_item.text()
            # 处理单元格数据

table_widget = QTableWidget()  # 创建QTableWidget对象

# 获取列数
column_count = table_widget.columnCount()

# 遍历列对象
for column_index in range(column_count):
    # 获取列对象
    column = table_widget.column(column_index)
    
    # 遍历列中的表格单元格数据
    for row_index in range(table_widget.rowCount()):
        cell_item = column.item(row_index)
        if cell_item is not None:
            cell_data = cell_item.text()
            # 处理单元格数据