Python中的 zip()

Python zip() 方法采用可迭代对象或容器并返回单个迭代器对象，该对象具有来自所有容器的映射值。

它用于 映射多个容器的相似索引，以便仅使用单个实体即可使用它们。

Syntax :  zip(*iterators) 

Parameters : Python iterables or containers ( list, string etc ) 
Return Value : Returns a single iterator object, having mapped values from all the 
containers.

Python zip() 示例

示例 1： Python压缩两个列表

Python3

name = [ "Manjeet", "Nikhil", "Shambhavi", "Astha" ]
roll_no = [ 4, 1, 3, 2 ]
 
# using zip() to map values
mapped = zip(name, roll_no)
 
print(set(mapped))

输出：

{('Shambhavi', 3), ('Nikhil', 1), ('Astha', 2), ('Manjeet', 4)}

示例 2： Python zip枚举

Python3

names = ['Mukesh', 'Roni', 'Chari']
ages = [24, 50, 18]
 
for i, (name, age) in enumerate(zip(names, ages)):
    print(i, name, age)

输出：

0 Mukesh 24
1 Roni 50
2 Chari 18

示例 3： Python zip() 字典

Python3

stocks = ['reliance', 'infosys', 'tcs']
prices = [2175, 1127, 2750]
 
new_dict = {stocks: prices for stocks,
            prices in zip(stocks, prices)}
print(new_dict)

输出：

{'reliance': 2175, 'infosys': 1127, 'tcs': 2750}

如何解压？

解压缩意味着将压缩后的值转换回原来的个体自我。这是在“ * ”运算符的帮助下完成的。

Python3

# Python code to demonstrate the working of
# unzip
 
# initializing lists
name = ["Manjeet", "Nikhil", "Shambhavi", "Astha"]
roll_no = [4, 1, 3, 2]
marks = [40, 50, 60, 70]
 
# using zip() to map values
mapped = zip(name, roll_no, marks)
 
# converting values to print as list
mapped = list(mapped)
 
# printing resultant values
print("The zipped result is : ", end="")
print(mapped)
 
print("\n")
 
# unzipping values
namz, roll_noz, marksz = zip(*mapped)
 
print("The unzipped result: \n", end="")
 
# printing initial lists
print("The name list is : ", end="")
print(namz)
 
print("The roll_no list is : ", end="")
print(roll_noz)
 
print("The marks list is : ", end="")
print(marksz)

输出：

The zipped result is : [('Manjeet', 4, 40), ('Nikhil', 1, 50), 
('Shambhavi', 3, 60), ('Astha', 2, 70)]


The unzipped result: 
The name list is : ('Manjeet', 'Nikhil', 'Shambhavi', 'Astha')
The roll_no list is : (4, 1, 3, 2)
The marks list is : (40, 50, 60, 70)

实际应用

有许多可能的应用程序可以说是使用 zip 执行的，无论是学生数据库还是记分卡，或者任何其他需要组映射的实用程序。下面展示了一个记分卡的小例子。

Python3

# Python code to demonstrate the application of
# zip()
 
# initializing list of players.
players = ["Sachin", "Sehwag", "Gambhir", "Dravid", "Raina"]
 
# initializing their scores
scores = [100, 15, 17, 28, 43]
 
# printing players and scores.
for pl, sc in zip(players, scores):
    print("Player :  %s     Score : %d" % (pl, sc))

输出：

Player :  Sachin     Score : 100
Player :  Sehwag     Score : 15
Player :  Gambhir     Score : 17
Player :  Dravid     Score : 28
Player :  Raina     Score : 43