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#Python 的解包操作

解包操作(Unpacking)允许我们将一个可迭代对象(如列表、元组、字典等)中的元素提取到多个变量中。

#序列解包

最常见的解包是从元组或列表中提取元素。例如:

student_info:tuple[str, int, str] = ("Yukari", 17, "female") name, age, sex = student_info print(name, age, sex)

>>> Establishing WebAssembly Runtime.

>>> Standby.

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直接对字典进行序列解包,得到的是字典的键。例如:

score_list:dict[str,int] = { 'Tom': 88, 'Jerry': 99, 'Spike': 66 } key1, key2, key3 = score_list print(key1, key2, key3)

>>> Establishing WebAssembly Runtime.

>>> Standby.

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#部分解包

可以在序列解包中使用下划线(_)忽略不需要的元素。例如:

students:list[str] = ["Tom", "Jerry", "Spike", "Tuffy"] first, _, _, last = students print(first, last)

>>> Establishing WebAssembly Runtime.

>>> Standby.

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#使用星号

使用星号(*)可以将元组、数组或集合拆分成独立的元素。例如:

students:list[str] = ["Tom", "Jerry", "Spike", "Tuffy", "Tyke", "Butch"] warp1 = [students] # warp1 变成了二维列表 list[list[str]] warp2 = [*students] # students 被解包,warp2 是 list[str] print(warp1) print(warp2)

>>> Establishing WebAssembly Runtime.

>>> Standby.

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可以在序列解包的左侧使用星号(*)获取多个元素。例如:

students:list[str] = ["Tom", "Jerry", "Spike", "Tuffy", "Tyke", "Butch"] first, *_, last = students # _ 是数组,获取多个元素 print(first, last)

>>> Establishing WebAssembly Runtime.

>>> Standby.

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#键值对解包

通过 items 方法可以获得字典的键值对元组的序列,从而可以通过序列解包获取字典的键值对。

score_list:dict[str,int] = { 'Tom': 88, 'Jerry': 99, 'Spike': 66 } # 查看键值对 print(score_list.items()) # 解包单个键值对 name, score = list(score_list.items())[0] print(name, score) # 通过键值对解包简化 for 循环 for key,value in score_list.items(): print(key, value)

>>> Establishing WebAssembly Runtime.

>>> Standby.

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#使用星号解包字典

使用 一个 星号(*)可以将字典拆分成独立的键,使用 两个 星号(*)可以将字典拆分成独立的键值对。例如:

score_list:dict[str,int] = { 'Tom': 88, 'Jerry': 99, 'Spike': 66 } wrap1 = {*score_list} # score_list 被拆分成独立的键,wrap1 是 set[str] wrap2 = {**score_list} # score_list 被拆分成独立的键值对,wrap2 是 dict[str,int] print(wrap1) print(wrap2)

>>> Establishing WebAssembly Runtime.

>>> Standby.

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创建于 2025/4/10

更新于 2025/6/9