如何有條件地從元組列表中刪除元素？

Question

>>> x=[("x1","x2","x3"),("x1","x2"),("x2","x3"),("x3","x4")] 
>>> x 
[('x1', 'x2', 'x3'), ('x1', 'x2'), ('x2', 'x3'), ('x3', 'x4')] 

我想刪除列表中的元組 - X，如果len(x[id])==3，len(x[0]==3)，所以它會被刪除，[('x1', 'x2'), ('x2', 'x3'), ('x3', 'x4')]就是我想要的，我怎麼能寫代碼？

[del element if len(element[id]==3) for id,element in enumerate(x)] 

invalid syntax. 

Answer 1

使用列表理解來過濾元素，保持一切不長3：

x = [el for el in x if len(el) != 3] 

演示：

>>> x = [('x1', 'x2', 'x3'), ('x1', 'x2'), ('x2', 'x3'), ('x3', 'x4')] 
>>> [el for el in x if len(el) != 3] 
[('x1', 'x2'), ('x2', 'x3'), ('x3', 'x4')]