Python:在列表列表中查找重复项以编辑它们

Question

在我的 python 项目中，我有一个这样的列表:

l1 = [['Bacon', 1995,'394'], ['Bacon', 1995, '39-46'], ['Bacon', 1998,'7'], ['Egg', 1998, '122-165'], ['Chicken', 2009, '10'], ['Shrimp', 1994, '67']]

我的目标是将列表写在 word 文档中，我的问题是当名称和年份在列表中重复时(如“培根”和“1995”)我想在一年让他们与众不同。所以结果应该是:

l1 = [['Bacon', 1995a,'394'], ['Bacon', 1995b, '39-46'], ['Bacon', 1998,'7'], ['Egg', 1998, '122-165'], ['Chicken', 2009, '10'], ['Shrimp', 1994, '67']]

我已经试过了:

n = ["a", "b", "c", "d", "e", "f", "g", "h"] # [...]

count = 0
for info in l1:
    if info[0] and info[1] in l1:
        print(f"{info[1]}{a[count]}")
#         para.add_run(info[0])
#         para.add_run(f"{info[1]}{n[count]}")
        count += 1     
    else:
        print(info[1])
#         para.add_run(info[0])
#         para.add_run(info[1])

并创建一个新列表，如下所示:

l2 = []
count = 0
for info in l1:
    if info[0] and info[1] in l2:
        l2.append(info[0], f"{info[1]}{a[count]}", info[2])
        count += 1     
    else:
        l2.append((info[0],info[1], info[2]))

但两者都不起作用。

Answer 1

一种使用 collections.defaultdict 的方法.首先在嵌套字典中收集所有内容，然后重新创建列表:

from collections import defaultdict
from string import ascii_letters

l1 = [['Bacon', 1995, '394'], ['Bacon', 1995, '39-46'],
      ['Bacon', 1998, '7'], ['Egg', 1998, '122-165'],
      ['Chicken', 2009, '10'], ['Shrimp', 1994, '67']]

index = defaultdict(lambda: defaultdict(list))

# collect
for food, year, page in l1:
    index[food][year].append(page)

# re-create list:
res = []
for food, rest in index.items():
    for year, pages in rest.items():
        if len(pages) == 1:
            res.append([food, year, pages[0]])
        else:
            for letter, page in zip(ascii_letters, pages):
                res.append([food, f"{year}{letter}", page])
print(res)

在收集阶段之后 index 看起来像这样(为了清楚起见，我去掉了 defaultdict):

{'Bacon': {1995: ['394', '39-46'], 1998: ['7']},
 'Chicken': {2009: ['10']},
 'Egg': {1998: ['122-165']},
 'Shrimp': {1994: ['67']}}

输出

[['Bacon', '1995a', '394'], ['Bacon', '1995b', '39-46'],
 ['Bacon', 1998, '7'], ['Egg', 1998, '122-165'],
 ['Chicken', 2009, '10'], ['Shrimp', 1994, '67']]

您可能还想将没有字母的 year 转换为字符串。这样列表中的类型是一致的。