fetch-daily-train-info

name	fetch-daily-train-info
description	Use when you need to get the daily train information from the 12306 train info repository

Fetch Daily Train Info

Overview

Get the latest daily train information by fetching it from GitHub Release using curl. The train info is updated daily and stored as a markdown file in the releases.

When to Use

• Need to get train information for a specific date
• Need historical train data for a specific date
• Need to update local train info cache

Important: You MUST ask the user for the specific date they want (YYYYMMDD format) if they haven't provided one. Don't assume a date automatically.

URL Pattern

The GitHub Release URL follows the pattern:

https://github.com/HerbertHe/cr-12306-train-info/releases/download/data-<YYYYMMDD>/train_detail_<YYYYMMDD>.md

Note: The release date is often for the next day. For example, data-20260414 contains train_detail_20260413.md.

Implementation

Fetch with curl

# For a specific date (YYYYMMDD format)
DATE=20260413
curl -f "https://github.com/HerbertHe/cr-12306-train-info/releases/download/data-${DATE}/train_detail_${DATE}.md" -o train_detail_${DATE}.md

Check Download Result

After downloading, always check if the file is empty:

# Check if file exists and is not empty
if [ ! -s "train_detail_${DATE}.md" ]; then
  echo "Error: Failed to download train data for date ${DATE}. The file is empty or does not exist."
  exit 1
fi

Example Usage

Get train info for a specific date

# Specify date manually (YYYYMMDD format)
DATE=20260413
curl -f "https://github.com/HerbertHe/cr-12306-train-info/releases/download/data-${DATE}/train_detail_${DATE}.md"

# Check if download succeeded and file is not empty
if [ ! -s "train_detail_${DATE}.md" ]; then
  echo "Error: Failed to download train data for date ${DATE}. The file is empty or does not exist."
  exit 1
fi

Save to file with check

DATE=20260413
curl -f "https://github.com/HerbertHe/cr-12306-train-info/releases/download/data-${DATE}/train_detail_${DATE}.md" -o train_detail_${DATE}.md

# Exit if download failed or file is empty
if [ ! -s "train_detail_${DATE}.md" ]; then
  echo "Error: Failed to download train data for date ${DATE}. The file is empty or does not exist."
  exit 1
fi

Common Mistakes

• Using the wrong date format (must be YYYYMMDD)
• Mismatching the date in the release path and file name
• Expecting today's data to exist before the day ends

After Fetching

After successfully fetching the data:

1. Count total trains: Count the total number of trains in the downloaded file (count table rows)
2. Inform customer: Tell the customer the total number of trains obtained
3. Ask for train type: Ask the user which train type they want:

Available options:

• 全部: All trains (show everything)
• 高速: Only high-speed trains (G - high-speed rail, C - intercity, D - EMU)
• 普通: Only conventional trains (S - suburban railway, K - express, T - express, Y - tourist, Z - direct express)

Wait for the user's selection before filtering and displaying the results.

Filtering with Python

Markdown Table Structure

The fetched markdown file has the following structure:

| 序号 | 车号(train_no) | 站点车次(station_train_code) | 站点(到站时间 - 发车时间 - 运行时间 - 到达日) | 站点数量(total_num) |

Filtering Script

Use this Python script to filter by train type and optionally by station keyword based on the first character of the train number and station name:

import re
import sys

def filter_trains(input_file, train_type, station_keyword=None):
    # Define patterns based on train type
    patterns = {
        '高速': r'^[GCD]',
        '普通': r'^[SKTYZ]',
        '全部': r'.*'
    }
    
    train_pattern = patterns.get(train_type, r'.*')
    
    with open(input_file, 'r', encoding='utf-8') as f:
        lines = f.readlines()
    
    # Keep header and separator (markdown file has title + table header)
    result = lines[:4]
    
    # Filter lines matching the pattern
    for line in lines[4:]:
        # Extract the first character of the visible train number
        # The actual data stores a hash in the second column, visible number is in third column
        visible_match = re.search(r'\|\s*\d+\s*\|\s*.*\|\s*([A-Za-z])', line)
        if not visible_match:
            continue
        
        first_char = visible_match.group(1)
        if not re.match(train_pattern, first_char):
            continue
        
        # If station keyword provided, check if it exists in the station column
        if station_keyword:
            # Extract the station column (fourth column)
            parts = line.split('|')
            if len(parts) >= 5:
                station_info = parts[4].strip()
                if station_keyword not in station_info:
                    continue
        
        result.append(line)
    
    # Print the result
    print(''.join(result))
    print(f"\n---")
    print(f"Total trains: {len(result) - 4}")

if __name__ == '__main__':
    if len(sys.argv) < 3:
        print("Usage: python filter_trains.py <input_file> <train_type> [station_keyword]")
        print("train_type: 全部, 高速, 普通")
        print("station_keyword: optional keyword to filter stations (e.g., 南京)")
        sys.exit(1)
    
    station_keyword = sys.argv[3] if len(sys.argv) >= 4 else None
    filter_trains(sys.argv[1], sys.argv[2], station_keyword)

Usage

# Filter by train type only
python filter_trains.py train_detail_YYYYMMDD.md 高速

# Filter by train type and station keyword (matches any station containing the keyword)
python filter_trains.py train_detail_YYYYMMDD.md 高速 南京

How Station Filtering Works

• If user provides a station name (e.g. "南京"), filters to show only trains that have the keyword in any of their stations
• This matches "南京站", "南京南站", "南京东站", etc.
• Uses simple substring matching, not exact match

Notes

• Data is updated daily by the repository maintainer
• The release tag is data-YYYYMMDD for the next day's release containing the previous day's data
• File is in markdown format with train details