如何从有序嵌套列表中移除重复的Vendor ID-Vendor Name条目？

输入示例 #

[['110220VOLTS0001', 'Vendor1'],
['Functional Amount Not Invoiced:', '$56.97'],
['2729426', 'Vendor2'],
['Functional Amount Not Invoiced:', '$1,000.00'],
['2955510', 'Vendor3'],
['2955510', 'Vendor3'],
['Functional Amount Not Invoiced:', '$329.00'],
['3466873', 'Vendor4'],
['Functional Amount Not Invoiced:', '$0.48']]

需求说明 #

列表包含两类条目：

• 第一类：['Vendor ID', 'Vendor Name']，可能重复出现
• 第二类：['Functional Amount Not Invoiced:', '$ Amount']，无重复，每个金额条目对应其前面最近的供应商条目

需要移除重复的供应商条目，同时保留原列表的顺序以及对应的金额条目，最终输出如下：

[['110220VOLTS0001', 'Vendor1'],
['Functional Amount Not Invoiced:', '$56.97'],
['2729426', 'Vendor2'],
['Functional Amount Not Invoiced:', '$1,000.00'],
['2955510', 'Vendor3'],
['Functional Amount Not Invoiced:', '$329.00'],
['3466873', 'Vendor4'],
['Functional Amount Not Invoiced:', '$0.48']]

解决方案 #

利用集合记录已出现的供应商（将列表转为元组存入集合，因为列表不可哈希），遍历原列表时做判断：

• 若为供应商条目（长度2且第一个元素不是固定金额标签），检查是否已在集合中，未出现则加入结果列表和集合
• 若为金额条目，直接加入结果列表

实现代码：

input_list = [
    ['110220VOLTS0001', 'Vendor1'],
    ['Functional Amount Not Invoiced:', '$56.97'],
    ['2729426', 'Vendor2'],
    ['Functional Amount Not Invoiced:', '$1,000.00'],
    ['2955510', 'Vendor3'],
    ['2955510', 'Vendor3'],
    ['Functional Amount Not Invoiced:', '$329.00'],
    ['3466873', 'Vendor4'],
    ['Functional Amount Not Invoiced:', '$0.48']
]

seen_vendors = set()
result = []

for item in input_list:
    # 判断是否为供应商条目：长度为2且第一个元素不是金额标签
    if len(item) == 2 and item[0] != 'Functional Amount Not Invoiced:':
        vendor_tuple = tuple(item)
        if vendor_tuple not in seen_vendors:
            seen_vendors.add(vendor_tuple)
            result.append(item)
    else:
        # 金额条目直接加入
        result.append(item)

# 打印结果
for row in result:
    print(row)

输出结果 #

运行上述代码后，得到的结果与预期一致：

[['110220VOLTS0001', 'Vendor1'],
['Functional Amount Not Invoiced:', '$56.97'],
['2729426', 'Vendor2'],
['Functional Amount Not Invoiced:', '$1,000.00'],
['2955510', 'Vendor3'],
['Functional Amount Not Invoiced:', '$329.00'],
['3466873', 'Vendor4'],
['Functional Amount Not Invoiced:', '$0.48']]

内容的提问来源于stack exchange，提问作者user19891327