Example of using the zip function in Python

This article describes how to use the zip function in Python. the zip function in Python is not used to compress files, but to pass in parameters to return a tuple list, if you need a tuple list, you can refer to the zip function below to accept any number of (including 0 and 1) sequences as parameters. The specific meaning is not easy to express in words. let's look at the example:

1. Example 1:

The code is as follows:

X = [1, 2, 3]
Y = [4, 5, 6]
Z = [7, 8, 9]
Xyz = zip (x, y, z)
Print xyz

The running result is:

[(1, 4, 7), (2, 5, 8), (3, 6, 9)]

The result shows the basic operation mode of the zip function.

2. Example 2:

The code is as follows:

X = [1, 2, 3]
Y = [4, 5, 6, 7]
Xy = zip (x, y)
Print xy

The running result is:

The code is as follows:

[(1, 4), (2, 5), (3, 6)]

The result shows the processing method of the zip function length.

3. Example 3:

The code is as follows:

X = [1, 2, 3]
X = zip (x)
Print x

The running result is:

The code is as follows:

[(1,), (2,), (3,)]

From this result, we can see that the zip function is run with only one parameter.

4. Example 4:

The code is as follows:

X = zip ()
Print x

The running result is:

The code is as follows:

[]

From this result, we can see how the zip function works without parameters.

5. Example 5:

The code is as follows:

X = [1, 2, 3]
Y = [4, 5, 6]
Z = [7, 8, 9]
Xyz = zip (x, y, z)
U = zip (* xyz)
Print u

The running result is:

The code is as follows:

[(1, 2, 3), (4, 5, 6), (7, 8, 9)]

It is generally considered that this is an unzip process, and its operating mechanism is as follows:

Before running zip (* xyz), the xyz value is: [(1, 4, 7), (2, 5, 8), (3, 6, 9)]

Then, zip (* xyz) is equivalent to zip (1, 4, 7), (2, 5, 8), (3, 6, 9 ))

Therefore, the running result is: [(1, 2, 3), (4, 5, 6), (7, 8, 9)]

Note: In function calls, the * list/tuple method is used to separate list/tuple and pass it as a location parameter to the corresponding function (provided that the corresponding function supports the location parameter with an indefinite number)

6. example 6:

The code is as follows:

X = [1, 2, 3]
R = zip (* [x] * 3)
Print r

The running result is:

The code is as follows:

[(1, 1, 1), (2, 2, 2), (3, 3, 3)]

Its operating mechanism is as follows:

[X] generates a list with only one element x

[X] * 3 generates a list with three elements: [x, x, x]

The meaning of zip (* [x] * 3) is clear. zip (x, x, x)