python 從元組列表中刪除 tup[0] 重復項

Question

input = [("abc", 2), ("def", 7), ("abc", 6), ("ghi", 2), ("ghi", 5)]

我想從列表中刪除 tup[0] 重復項("abc", 6)和("ghi", 5) ，因此 output 應該是：

output = [("abc", 2), ("def", 7), ("ghi", 2)]

我該怎么做呢？

Answer 1

有更優雅的解決方案，但這很有效。

input = [("abc", 2), ("def", 7), ("abc", 6), ("ghi", 2), ("ghi", 5)]

output = []
first_tups = []

for tup in input:
    if tup[0] not in first_tups:
        output.append(tup)
        first_tups.append(tup[0])

print(output)

output

[('abc', 2), ('def', 7), ('ghi', 2)]

Answer 2

只需使用一set來跟蹤您已經看到的第一個項目：

>>> input_data = [("abc", 2), ("def", 7), ("abc", 6), ("ghi", 2), ("ghi", 5)]
>>> seen = set()
>>> result = []
>>> for tup in input_data:
...     s = tup[0]
...     if s not in seen:
...         seen.add(s)
...         result.append(tup)
...
>>> result
[('abc', 2), ('def', 7), ('ghi', 2)]