Python – 元组列表中的交叉配对

给定 2 个元组，执行对应元组的交叉配对，如果两个元组的第一个元素匹配，则转换为单个元组。

Input : test_list1 = [(1, 7), (6, 7), (8, 100), (4, 21)], test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)]
Output : [(7, 3)]
Explanation : 1 occurs as tuple element at pos. 1 in both tuple, its 2nd elements are paired and returned.

Input : test_list1 = [(10, 7), (6, 7), (8, 100), (4, 21)], test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)]
Output : []
Explanation : NO pairing possible.

方法#1：使用列表推导

在此，我们使用条件语句检查第一个元素，并在列表理解中构造新元组。

Python3

# Python3 code to demonstrate working of 
# Cross Pairing in Tuple List
# Using list comprehension
  
# initializing lists
test_list1 = [(1, 7), (6, 7), (9, 100), (4, 21)]
test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)]
  
# printing original lists
print("The original list 1 : " + str(test_list1))
print("The original list 2 : " + str(test_list2))
  
# corresponding loop in list comprehension
res = [(sub1[1], sub2[1]) for sub2 in test_list2 for sub1 in test_list1 if sub1[0] == sub2[0]]
  
# printing result 
print("The mapped tuples : " + str(res))

输出

The original list 1 : [(1, 7), (6, 7), (9, 100), (4, 21)]
The original list 2 : [(1, 3), (2, 1), (9, 7), (2, 17)]
The mapped tuples : [(7, 3), (100, 7)]

方法 #2：使用 zip() + 列表理解

在这种情况下，配对任务是使用 zip() 完成的，条件检查是在列表理解中完成的。

Python3

# Python3 code to demonstrate working of 
# Cross Pairing in Tuple List
# Using zip() + list comprehension
  
# initializing lists
test_list1 = [(1, 7), (6, 7), (9, 100), (4, 21)]
test_list2 = [(1, 3), (2, 1), (9, 7), (2, 17)]
  
# printing original lists
print("The original list 1 : " + str(test_list1))
print("The original list 2 : " + str(test_list2))
  
# zip() is used for pairing 
res = [(a[1], b[1]) for a, b in zip(test_list1, test_list2) if a[0] == b[0]]
  
# printing result 
print("The mapped tuples : " + str(res))

输出

The original list 1 : [(1, 7), (6, 7), (9, 100), (4, 21)]
The original list 2 : [(1, 3), (2, 1), (9, 7), (2, 17)]
The mapped tuples : [(7, 3), (100, 7)]