Python 检查两边的括号是否相等，如果不相等，找出多余的并说出它们的位置

Question

我写了一个代码，但不知道如何让它找到额外的不平衡括号这是我的代码

def checkBalance(str1):
count = 0
for i in str1:
    if i == "(" or i == "{" or i == "[":
        count += 1
    elif i == ")" or i == "}" or i == "]":
        count -= 1
    if count < 0:
        return False and str1.find(")")
return count == 0 

str1 = input("Enter a string of brackets: ")
print("Given string is balanced :", checkBalance(str1))

例如，如果我输入 ()()()，代码会说它是平衡的，但如果我输入类似这样的内容 (()))，它会说它不平衡，我想添加的是它会说代码是否平衡，并说不平衡的边的第一个位置，如 CODE IS NOT BALANCED ")" POSTITION 3 和如果另一个不平衡，我也想这样做 ((()) CODE IS NOT BALANCED "(" POSTITION 1

Answer 1

试试这个：在每次迭代中，最里面的括号被替换为空字符串。如果最终字符串为空，则其平衡不平衡。

def checkBalance(check_string):
    brackets = ['()', '{}', '[]']
    while any(item in check_string for item in brackets):
        for br in brackets:
            check_string = check_string.replace(br, '')
    return not check_string
   
str1 = input("Enter a string of brackets: ")
print("Given string:", str1, "is", "Balanced" if checkBalance(str1) else "Not balanced")

Answer 2

我很快写了一些可以解决您的问题的东西。抱歉有点乱。我也把它做得更精致一点（不混合括号类型等）。

以下相关部分，我想可能对您有很大帮助：

enumerate 函数可让您遍历某些内容，给出给定条目的值和位置（此处为教程示例：https://www.geeksforgeeks.org/enumerate-in-python/）
f-strings 是将变量合并到字符串中的好方法。只需在字符串前面加上一个 f，然后将变量放在大括号中即可。

因此，如果您想自己尝试，我建议您查看 enuemrate 和 f-strings。否则你可以使用下面的函数。

def checkBalance(str1: str) -> str:
    """ Checks if there is unmatched brackets.
    
    :param str: The string that shall be checked
    ...
    :returns: A message detailing if and where brackets are unmatched.
    """
    
    brackets = {"curly": {"open": "{",
                          "close": "}",
                          "count": 0},
                "round": {"open": "(",
                          "close": ")",
                          "count": 0},
                "square": {"open": "[",
                           "close": "]",
                           "count": 0}
    }
    
    for pos, i in enumerate(str1):
        for bracket in brackets:
            if i == brackets[bracket]["open"]:
                brackets[bracket]["count"] += 1
    
                for name in brackets:
                    if name != bracket:
                        if brackets[name]["count"] != 0:
                            return f"Error, opening {bracket} bracket before {name} bracket shut at position {pos}."
    
            if i == brackets[bracket]["close"]:
                brackets[bracket]["count"] -= 1
                if brackets[bracket]["count"] < 0:
                    return f"Error, closing {bracket} bracket at position {pos} without opening bracket"
    
    return_val = ""
    for name, info in brackets.items():
        if info["count"] > 0:
            return_val += f"You have {info['count']} unmatched opening {name} brackets \n"
    
    if return_val != "":
        return return_val
    
    return "No problems with your brackets."

Python 检查两边的括号是否相等，如果不相等，找出多余的并说出它们的位置

Python Check whether the parentheses are equal on both sides and if they are not find the extra ones and say their positions

python

position

find