类与对象 —— 属性和方法

class Trainee:                        # ① 定义模具：class 类名:（类名约定首字母大写）
  def __init__(self, name, weight):  # ② 出厂设置：造对象时自动执行
      self.name = name               # ③ 把参数存成属性：挂在 self 身上
      self.weight = weight

  def report(self):                  # ④ 方法：定义在类里的函数，第一个参数是 self
      return f"{self.name}：当前 {self.weight} 公斤"


ada = Trainee("小雨", 55)              # ⑤ 造对象：类名(参数)，自动触发 __init__
print(ada.report())                    # ⑥ 用对象：对象.方法()
print(ada.weight)                      # ⑦ 属性也能直接读：对象.属性

class Trainee:
  def __init__(self, name, weight):
      self.name = name
      self.weight = weight

  def report(self):
      return f"{self.name}：当前 {self.weight} 公斤"


ada = Trainee("小雨", 55)
bob = Trainee("大壮", 88)

print(ada.report())   # self 是 ada：说明书套用在小雨身上
print(bob.report())   # self 是 bob：同一份说明书，主角换了

# 谜底：ada.report() 其实是 Python 帮你写了 Trainee.report(ada)
print(Trainee.report(ada))   # 和 ada.report() 完全等价——self 就是这么传进去的

class Trainee:
  def __init__(self, name, weight):
      self.name = name
      self.weight = weight
      self.sessions = 0          # 属性也可以不来自参数：出厂即 0

  def train(self, hours=1):
      self.sessions = self.sessions + 1
      self.weight = self.weight - 0.2 * hours   # 练一小时掉 0.2 公斤（美好假设）
      print(f"{self.name} 完成第 {self.sessions} 次训练")

  def report(self):
      return f"{self.name}：{self.weight:.1f} 公斤，累计 {self.sessions} 次课"


ada = Trainee("小雨", 55)
ada.train()
ada.train(hours=2)
print(ada.report())

class Trainee:
  def __init__(self, name, weight):
      self.name = name
      self.weight = weight

  def __str__(self):                 # 教对象"自我介绍"：print 时自动调用
      return f"学员 {self.name}（{self.weight} 公斤）"


ada = Trainee("小雨", 55)
print(ada)          # 有 __str__：说人话
print(str(ada))     # str() 转换时也走它

class Wallet:
  """记账钱包：存钱、花钱、查余额"""            # docstring：类也配说明

  def __init__(self, owner, balance=0):
      self.owner = owner
      self.balance = balance
      self.records = []                        # 属性可以是列表：容器随便用

  def earn(self, amount, note=""):
      self.balance = self.balance + amount
      self.records.append(f"+{amount} {note}")

  def spend(self, amount, note=""):
      if amount > self.balance:                # 方法里照样写业务检查
          print(f"余额不足：想花 {amount}，只有 {self.balance}")
          return
      self.balance = self.balance - amount
      self.records.append(f"-{amount} {note}")

  def __str__(self):
      return f"{self.owner} 的钱包：余额 {self.balance} 元，{len(self.records)} 笔记录"


w = Wallet("阿杰", balance=100)
w.earn(3000, "工资")
w.spend(88, "键盘")
w.spend(9999, "显卡")     # 会被拦下
print(w)
print(w.records)

# 修好下面的类
class Timer:
  def __init__(self, task):
      self.task = task
      self.minutes = 0

  def add(minutes):
      self.minutes = self.minutes + minutes

  def report(self):
      return f"{task} 已计时 {self.minutes} 分钟"


t = Timer("写周报")
t.add(25)
print(t.report())

# 你的代码写在下面

class Ticket:
  def __init__(self, customer, issue, status="待处理"):
      self.customer = customer
      self.issue = issue
      self.status = status

  def close(self):
      self.status = "已解决"

  def __str__(self):
      return f"[{self.status}] {self.customer}：{self.issue}"


# 你的代码写在下面