删除具有给定条件的重复项和 python 中的 return 唯一元组列表

Question

我有一个元组列表如下：

ls = [("red", "apple"), ("black", "grapes"),
      ("green", "apple"), ("yellow", "banana"),
      ("white", "litchi"), ("brown", "grapes")]

如果你注意到，我有红色和绿色的“苹果”以及黑色和棕色的“葡萄”。所以我想删除任何一个元组并保留另一个元组，输出应如下所示：

output = [("red", "apple"), ("black", "grapes"),
          ("yellow", "banana"), ("white", "litchi")]

所以在输出中 (green apple) 和 (brown grapes) 被删除了。

有什么办法可以实现吗？我尝试了很多次，但无法弄清楚。请帮助.. :)

Answer 1

如果需要按元组的第二个值删除重复项，请使用 DataFrame.drop_duplicates:

a = pd.DataFrame(ls).drop_duplicates([1]).apply(tuple, 1).tolist()
print (a)
[('red', 'apple'), ('black', 'grapes'), ('yellow', 'banana'), ('white', 'litchi')]

Answer 2

我设法将列表转换为 Pandas DataFrame，根据“水果”属性删除重复项，然后将其转换回元组列表。

import pandas as pd

ls = [("red", "apple"), ("black", "grapes"),
      ("green", "apple"), ("yellow", "banana"),
      ("white", "litchi"), ("brown", "grapes")]

df = pd.DataFrame (ls, columns=["color", "fruit"])
df.drop_duplicates (subset=["fruit"], keep="first", inplace=True)

print (list(df.to_records(index=False)))

Answer 3

pandas 太过分了。它可以在不导入任何额外模块的情况下完成。

创建一个中间字典，然后从中重建元组列表：

ls = [("red", "apple"), ("black", "grapes"),
      ("green", "apple"), ("yellow", "banana"),
      ("white", "litchi"), ("brown", "grapes")]

d = [(v, k) for k, v in {v:k for k, v in ls}.items()]

print(d)

输出：

[('green', 'apple'), ('brown', 'grapes'), ('yellow', 'banana'), ('white', 'litchi')]

删除具有给定条件的重复项和 python 中的 return 唯一元组列表

Remove duplicates with a given condition and return unique list of tuples in python

python

tuples

list

python-3.x

pandas