用Python创建顺序栈的结构、出栈、入栈、取栈顶元素算法： 2. 创建判断表达式括号匹配、判断运算符、运算符优先级和两数运算的函数： 3.实现中缀表达式求值算法：

1. 创建顺序栈的结构、出栈、入栈、取栈顶元素算法:

顺序栈可以使用Python中的列表来实现。定义一个空列表来表示空栈，使用append()方法实现入栈操作，使用pop()方法实现出栈操作并返回被移除元素。使用[-1]索引来取栈顶元素。

以下是示例代码：

class Stack():
    def __init__(self):
        self.items = []
        
    def is_empty(self):
        return self.items == []
    
    def push(self, item):
        self.items.append(item)
        
    def pop(self):
        return self.items.pop()
    
    def peek(self):
        return self.items[-1]

2. 创建判断表达式括号匹配、判断运算符、运算符优先级和两数运算的函数：

可以使用栈来实现表达式求值。先将操作数压入栈中，当遇到运算符时，取出相应的操作数按照运算符计算，将结果再次压入栈中。最后栈中剩余的操作数即为最终结果。

以下是示例代码：

def is_operator(c):
    return c in ['+', '-', '*', '/']

def operator_priority(operator):
    return {'+': 1, '-': 1, '*': 2, '/': 2}[operator]

def calculate(num1, num2, operator):
    if operator == '+':
        return num1 + num2
    elif operator == '-':
        return num1 - num2
    elif operator == '*':
        return num1 * num2
    elif operator == '/':
        return num1 / num2
    
def evaluate_expression(expression):
    stack_num = []
    stack_operator = []
    
    for c in expression:
        if c.isdigit():
            stack_num.append(int(c))
        elif is_operator(c):
            while stack_operator and operator_priority(stack_operator[-1]) >= operator_priority(c):
                num2 = stack_num.pop()
                num1 = stack_num.pop()
                operator = stack_operator.pop()
                result = calculate(num1, num2, operator)
                stack_num.append(result)
            stack_operator.append(c)
        elif c == '(':
            stack_operator.append(c)
        elif c == ')':
            while stack_operator and stack_operator[-1] != '(':
                num2 = stack_num.pop()
                num1 = stack_num.pop()
                operator = stack_operator.pop()
                result = calculate(num1, num2, operator)
                stack_num.append(result)
            stack_operator.pop()
    
    while stack_operator:
        num2 = stack_num.pop()
        num1 = stack_num.pop()
        operator = stack_operator.pop()
        result = calculate(num1, num2, operator)
        stack_num.append(result)
        
    return stack_num[0]

3. 实现中缀表达式求值算法：

实现中缀表达式求值算法的思路与上述样例类似。在算法中，需要将中缀表达式转为后缀表达式，在后缀表达式中进行求值。

以下是示例代码：

def infix_to_postfix(expression):
    stack_operator = []
    postfix = []
    
    for c in expression:
        if c.isdigit():
            postfix.append(c)
        elif is_operator(c):
            while stack_operator and stack_operator[-1] != '(' and operator_priority(stack_operator[-1]) >= operator_priority(c):
                postfix.append(stack_operator.pop())
            stack_operator.append(c)
        elif c == '(':
            stack_operator.append(c)
        elif c == ')':
            while stack_operator and stack_operator[-1] != '(':
                postfix.append(stack_operator.pop())
            stack_operator.pop()
    
    while stack_operator:
        postfix.append(stack_operator.pop())
        
    return postfix

def evaluate_infix_expression(expression):
    postfix = infix_to_postfix(expression)
    stack = []
    
    for c in postfix:
        if c.isdigit():
            stack.append(int(c))
        elif is_operator(c):
            num2 = stack.pop()
            num1 = stack.pop()
            result = calculate(num1, num2, c)
            stack.append(result)
    
    return stack[0]