Python中如何去除两个关联列表的重复配对项？

Hey there! Let's sort out this duplicate pair issue for your email content. The goal is to keep only the first occurrence of each (list_I element, list_II element) pair, right? Here's a straightforward, efficient way to do this in Python:

Step-by-Step Solution #

First, we'll track which pairs we've already seen using a set (since set lookups are fast), then iterate through both lists in lockstep, building our new lists only with unique, first-seen pairs.

# Your original lists (note: I've added quotes to string values for valid Python syntax)
list_I = [123, 453, 444, 555, 123, 444]
list_II = ['A', 'A', 'B', 'C', 'A', 'B']

# Initialize a set to track seen pairs, plus empty new lists
seen_pairs = set()
New_list_I = []
New_list_II = []

# Iterate through paired elements from both lists
for val_i, val_ii in zip(list_I, list_II):
    current_pair = (val_i, val_ii)
    # Only keep the pair if we haven't seen it before
    if current_pair not in seen_pairs:
        seen_pairs.add(current_pair)
        New_list_I.append(val_i)
        New_list_II.append(val_ii)

# Verify the results
print(New_list_I)  # Output: [123, 453, 444, 555]
print(New_list_II)  # Output: ['A', 'A', 'B', 'C']

How This Works #

• zip(list_I, list_II) lets us loop through corresponding elements from both lists at the same time, creating pairs like (123, 'A'), (453, 'A'), etc.
• The seen_pairs set keeps track of every pair we've already added to our new lists. Since sets don't allow duplicates, checking if a pair exists is quick and efficient.
• We only add elements to New_list_I and New_list_II when their pair is encountered for the first time, which preserves the original order while eliminating duplicate pairs.

If your list_II values are not strings (e.g., custom objects), just make sure they're hashable (most built-in types like numbers, strings, tuples are). If you're working with custom classes, you'll need to implement the __hash__ and __eq__ methods for this approach to work.

内容的提问来源于stack exchange，提问作者GND