zip() 函数用于将可迭代的对象作为参数，将对象中对应的元素打包成一个个元组，然后返回由这些元组组成的列表。
如果各个迭代器的元素个数不一致，则返回列表长度与最短的对象相同，利用 * 号操作符，可以将元组解压为列表。
Definition and Usage
The zip() function returns a zip object, which is an iterator of tuples where the first item in each passed iterator is paired together, and then the second item in each passed iterator are paired together etc.
If the passed iterators have different lengths, the iterator with the least items decides the length of the new iterator.
zip 方法在 Python 2 和 Python 3 中的不同：在 Python 3.x 中为了减少内存，zip() 返回的是一个对象。如需展示列表，需手动 list() 转换。
Syntax
zip(iterator1, iterator2, iterator3 ...)
Parameter Values
Parameter Description
iterator1, iterator2, iterator3 ...
Iterator objects that will be joined together
Example
Join two tuples together:
a = ("John", "Charles", "Mike")
b = ("Jenny", "Christy", "Monica")
x = zip(a, b)
#use the tuple() function to display a readable version of the result:
print(tuple(x))
More Examples
Example
If one tuple contains more items, these items are ignored:
a = ("John", "Charles", "Mike")
b = ("Jenny", "Christy", "Monica", "Vicky")
x = zip(a, b)
#use the tuple() function to display a readable version of the result:
print(tuple(x))
>>>a = [1,2,3]
>>> b = [4,5,6]
>>> c = [4,5,6,7,8]
>>> zipped = zip(a,b) # 打包为元组的列表
[(1, 4), (2, 5), (3, 6)]
>>> zip(a,c) # 元素个数与最短的列表一致
[(1, 4), (2, 5), (3, 6)]
>>> zip(*zipped) # 与 zip 相反，*zipped 可理解为解压，返回二维矩阵式
[(1, 2, 3), (4, 5, 6)]