The train ticket for the Spring Festival of 2018 is on sale today. You can use Python to grab a ticket and go home for the New Year.

The train ticket for the Spring Festival of 2018 is on sale today. You can use Python to grab a ticket and go home for the New Year.

Author protream

Original article: http://www.jianshu.com/p/f411d7e10c41

Note: This article is an article edited by protream and marvin.

First, let's take a look at how to quickly view the remaining train tickets?

When you want to query the train ticket information, do you still go to the 12306 official website? Or open the APP on your phone? Next, let's use Python to write a line-of-command train ticket viewer. You only need to type a line of command on the command line to get the desired train ticket information! If you have just mastered the basics of Python, this will be a good little exercise.

Interface Design

An application is ultimately intended for use, even if it is for your own use. So first, you should think about how you want to use it? Let's give a name to this small application first. Since it is used to query ticket information, it is calledticketsOkay. We hope that users can get the desired information as long as they enter the origin site, arrival site, and date.ticketsIt should be used as follows:

$ tickets from to date

In addition, there are various types of trains: high-speed trains, bullet trains, express trains, fast trains, and direct trains. We hope to provide options to query only one or more specific trains, we should have the following options:

• -G high-speed trains

• -D EMU

• -T express

• -K fast

• -Z direct

These options should be used in combination. Therefore, our interface should look like this:

$ tickets [-gdtkz] from to date

The interface has been fixed, and the rest is to implement it.

Development Environment

A good practice for writing Python programs is to usevirtualenvThis tool creates a virtual environment. Our program is developed using Python3. Next we will create a folder in your working directory.ticketsTo create a virtual environment:

$ virtualenv -p /usr/bin/python3 venv

Run the following command to activate it:

$ . venv/bin/activate

Resolution Parameters

Python has many tools for writing command line applications, such as argparse, docopt, options... Here, we use the simple and easy-to-use tool docopt. We should install it first:

$ pip3 install docopt

Docopt can parse parameters according to the format defined in the document string.tickets.pyMedium:

# Coding: UTF-8

"Train tickets query by command-line.Usage: tickets [-gdtkz] <from> <to> <date> Options:-h, -- help display help menu-g -d -t -k z-z Example: tickets Nanjing Beijing 2016-07-01 tickets-dg Nanjing Beijing 2016-07-01 """

From docopt import docopt

Def cli (): "command-line interface" arguments = docopt (_ doc _) print (arguments)

If _ name _ = '_ main _': cli ()

Run the following program:

$ Python3 tickets. py Shanghai Beijing

The following Parameter Parsing result is obtained:

{'-D': False,'-G': False, '-k': False,'-t': False, '-Z': False, '<date>': '2017-07-01 ',' <from> ': 'shanghai',' <to> ': 'beijing '}

Get Data

The parameters have been parsed. The following describes how to obtain the data, which is also the most important part. First, open 12306 to go to the ticket remaining query page. If you use chrome, pressF12Open the developer tool and selectNetworkIn the query box, enterShanghaiToBeijing, Date2016-07-01Click query. We found in the debugging tool that the query system actually requested this URL.

https://kyfw.12306.cn/otn/lcxxcx/query?purpose_codes=ADULT&queryDate=2016-07-01&from_station=SHH&to_station=BJP

And the returned result isJsonFormat data! Next, the problem is simple. We only need to construct the request URL and parse the returned Json data. But we found thatfrom_stationAndto_stationIt is not a Chinese character, but a code, and the user inputs a Chinese character. How do we get the code? Open the web page source code to see if there is any discovery.

Aha! Sure enough, we found this link in the web page: https://kyfw.12306.cn/otn/resources/js/framework/station_name.js? Station_version = 1.8955. It seems to contain Chinese names, Pinyin, abbreviations, and codes of all stations. We save itstations.html. However, this information is crowded together, and we only want the code information of Chinese names and uppercase letters. What should we do?

BINGO! Regular Expression. Let's write a small script to match and extract the desired information. In parse. py:

# coding: utf-8

import re
from pprint import pprint

with open('stations.html', 'r') as f:    text = f.read()    stations = re.findall(u'([\u4e00-\u9fa5]+)\|([A-Z]+)', text)    pprint(dict(stations), indent=4)

We run this script, which returns all the stations and their uppercase letters and codes in a dictionary and redirects the resultsstations.pyMedium,

$ python3 parse.py > stations.py

We add a name for this dictionary,stations, Eventually,stations.pyThe file is as follows:

Stations = {'one Fort ': 'yjt', 'upgrade': 'ypetab',... 'long Zhen ': 'lza', 'Keel dian': 'lgm'
}

Now, if you enter the Chinese name of the station, we can directly obtain its letter code from the dictionary:

...
From stations import stations

Def cli (): arguments = docopt (_ doc _) from_staion = stations. get (arguments ['<from>']) to_station = stations. get (arguments ['<to>']) date = arguments ['<date>'] # Build URL url = 'https: // kyf201712306.cn/otn/lcxxcx/query? Purpose_codes = ADULT & queryDate ={}& from_station ={}& to_station ={} '. format (date, from_staion, to_station)

Everything is ready. Let's request this URL for data! Here we userequestsInstall this library first:

$ pip3 install requests

It provides very easy-to-use interfaces,

...
Import requests

Def cli ():... # Add the verify = False parameter. Do not verify the certificate r = requests. get (url, verify = False) print (r. json ())

From the results, we can see that the information related to the ticket needs to be further extracted:

def cli():    ...    r = requsets.get(url);    rows = r.json()['data']['datas']

Display result

The data has been obtained, and the rest is to extract the information we need and display it.prettytableThis database allows us to format and display data like the MySQL database.

$ pip3 install prettytable

Use it like this:

...
From prettytable import PrettyTable

Def cli ():... headers = 'train station time lasted business first class second class soft sleeper hard sleeper soft seat no seat '. split () pt = PrettyTable () pt. _ set_field_names (headers)
For row in rows:
# Filter information from the row according to headers, and then call pt. add_row () to add it to the table... print (pt)

Next, let's take a look at how to automatically grab:

From: Python Chinese community (No.: python-china)

Author: marvin, Internet practitioner, now lives in Zhangjiang, Shanghai

You can use Python + Splinter to automatically refresh the ticket to get the ticket. (Depending on your own network environment is too powerful, there are good or bad machines)

Splinter is an open-source Web application testing tool developed using Python. It can help you automatically browse the site and interact with it. When executing Splinter, it will automatically open your specified browser, access the specified URL. Then, any simulated behavior you develop will be automatically completed. You just need to sit in front of your computer and watch the various actions on the screen like watching a movie and then collect the results.

Python code snippet for 12306 ticket snatching

1. Functions for Automatic Logon:

2. Functions for ticket purchase

Source code download: Https://pan.baidu.com/s/1eSClOXW

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