如何从多项式字符串中获得系数和指数？

import re

def get_coefficient_and_exponent(poly_string):
    terms = re.split(r'\+|-', poly_string)  # 分割项
    coefficient_exponent_pairs = []
    
    for term in terms:
        match = re.match(r'(-?\d+)?x\^(-?\d+)?', term)  # 匹配系数和指数
        if match:
            coefficient = int(match.group(1)) if match.group(1) else 1
            exponent = int(match.group(2)) if match.group(2) else 1
            coefficient_exponent_pairs.append((coefficient, exponent))
    
    return coefficient_exponent_pairs

# 示例用法
poly_string = "3x^2 - 5x + 2"
pairs = get_coefficient_and_exponent(poly_string)
for pair in pairs:
    coefficient, exponent = pair
    print("系数:", coefficient)
    print("指数:", exponent)