第一步：生成一个字典，关键字包含年龄，姓名，性别。

info = {"年龄": 25, "姓名": "张三", "性别": "男"}

第二步：生成三个字典，并把他们追加到列表中。

info_list = []
info1 = {"年龄": 30, "姓名": "李四", "性别": "女"}
info2 = {"年龄": 28, "姓名": "王五", "性别": "男"}
info3 = {"年龄": 22, "姓名": "赵六", "性别": "女"}

info_list.append(info1)
info_list.append(info2)
info_list.append(info3)

第三步：把列表用open()写入到内存中。

with open("info_list.txt", "w") as f:
    for info in info_list:
        f.write(str(info) + "
")

第四步：设计一个修改模块，能够修改他们的年龄姓名性别等。修改完后追加到文件中。

def modify_info(old_info, key, value):
    old_info[key] = value
    return old_info

def append_to_file(file_name, info):
    with open(file_name, "a") as f:
        f.write(str(info) + "
")

for info in info_list:
    print("修改前：", info)
    modified_info = modify_info(info, "年龄", 26)
    modified_info = modify_info(modified_info, "姓名", "钱七")
    modified_info = modify_info(modified_info, "性别", "女")
    print("修改后：", modified_info)
    append_to_file("info_list.txt", modified_info)