Question

我正在写一个小练习程序来配对左右括号。如何减少嵌套for / if到一行？我试过了pure += [char for char in expression if char in brackets else '']，但它没有用。这是我想要减少的完整代码。

 def pair(expression):
        left=("(","[","{")
        right=(")","]","}")
        brackets=left+right
        print(brackets)
        pure=''

        #the part I want to reduce
        for char in expression:
            if char in brackets:
                pure+=char

Answer 1

这应该做你想要的

''.join([_ if _ in brackets else '' for _ in expression])

虽然正如其他人在评论中指出的那样，这根本没有任何意义。

全功能

def pair(expression):
    left = ("(", "[", "{")
    right = (")", "]", "}")
    brackets = left + right
    print(brackets)
    pure = ''.join([_ if _ in brackets else '' for _ in expression])

如何在Python中将这种嵌套条件减少到一行？

1 个答案: