序列解包

 序列解包：

  格式：变量a，变量b....(多个变量）= 可迭代对象

#迭代器：map(函数，可迭代对象）

案例：  info = "guohan|222|20"  a,b,c = info.split("|")     info.split("|")成为列表：可迭代  将guohan    222    20 赋值给a b c

      比如将info以|分割后的元素变成字典的value：    

info = "guohan|123|20"
name,pwd,age = info.split("|")
a = {"Name":name,"Pwd":pwd,"Age":age}  #变量的使用在其定义后前即不可以将2 3两行换位置
print(a)
>>>{'Name': 'guohan', 'Pwd': '123', 'Age': '20'}

列表元组解包：

# 列表解包
data = [10, 20, 30]
a, b, c = data
print(a)  # 输出: 10
print(b)  # 输出: 20
print(c)  # 输出: 30

# 元组解包
info = ("Alice", 25, "Engineer")
name, age, job = info
print(name)  # 输出: Alice
print(age)   # 输出: 25
print(job)   # 输出: Engineer

字符串解包：

text = "ABC"
x, y, z = text
print(x)  # 输出: A
print(y)  # 输出: B
print(z)  # 输出: C

解包时忽略部分元素：如果只需要序列中部分元素  可以用_进行占位忽略掉部分元素

data = [1, 2, 3, 4, 5]
first, _, third, _, fifth = data
print(first)  # 输出: 1
print(third)  # 输出: 3
print(fifth)  # 输出: 5

解包不定长度的序列：用*捕获多个元素（会被打包成列表）,其余元素按顺序赋值

# 捕获前两个元素，剩余元素给 rest
numbers = [1, 2, 3, 4, 5]
a, b, *rest = numbers
print(a)    # 输出: 1
print(b)    # 输出: 2
print(rest) # 输出: [3, 4, 5]

# 捕获中间元素
data = ["Alice", 25, "Engineer", "New York"]
name, *details, city = data
print(name)    # 输出: Alice
print(details) # 输出: [25, "Engineer"]
print(city)    # 输出: New York

 

 

 

题目：函数的定义+数据类型+序列解包

#打开文件并指定格式函数

#打开文件并指定格式函数
def get_file(file_path):
    a_list = list()
    with open(file_path,"r",encoding = "utf-8") as result:
        for line in result:
            line.strip()
            a_list.append(line.strip())
    print(a_list)
def get_file1(file_path):
    a_list = list()
    with open(file_path,"r",encoding = "utf-8") as result:
        for line in result:
            line.strip().split("|")
            a_list.append(line.strip().split("|"))
    print(a_list)
def get_file2(file_path):
    a_list = list()
    with open(file_path,"r",encoding = "utf-8") as result:
        for line in result:
            line.strip().split("|")
            name,pwd,age = line.strip().split("|")
            data = {"Name":name,"Pwd":pwd,"Age":age}
            a_list.append(data)
    print(a_list)
get_file("np.txt")
get_file1("np.txt")
get_file2("np.txt")