expr-metro-reversed-names

Analysis of reversed metro station names in China and globally.

Question

全国的轨道交通中，有哪些像广州地铁6号线的河沙、沙河这样，一条线路上两个站名刚好互相颠倒的例子？

Findings

Same Line Character Reversal (1 pair)

City	Line	Stations
广州	6号线	河沙 ↔ 沙河

This is the only example in China!

Same City Cross-Line Reversal (1 pair)

City	Stations	Lines
成都	光明 ↔ 明光	30号线 ↔ 19号线

Cross-City Reversals (9 pairs)

Station 1	City 1	Station 2	City 2
龙华	深圳/上海/长沙	华龙	重庆
福永	深圳	永福	杭州
平安	重庆	安平	福州
新立	天津	立新	东莞
水泉	沈阳	泉水	大连
岭北	南昌	北岭	青岛
平西	佛山	西平	东莞
光明	深圳/成都	明光	成都
沙河	北京/广州	河沙	广州

Homophones (2 pairs)

City	Stations	Pinyin
北京	关庄 = 管庄	guānzhuāng
广州	晓港 = 萧岗	xiǎogǎng

Palindrome Stations (6)

• 园博园: Beijing, Shijiazhuang, Jinan, Wuhan, Chongqing
• 北海北: Beijing Line 6

Data Source

• Gaode Map Subway API: https://map.amap.com/service/subway?srhdata={city_code}_drw_{city}.json
• Coverage: 31 cities, 291 lines, 6,462 stations

Scripts

• analyze_metro.py - Basic same-line reversal analysis
• analyze_metro_extended.py - Extended analysis with palindromes
• analyze_relaxed.py - Relaxed constraints (cross-line, pinyin)
• analyze_nationwide.py - Cross-city nationwide analysis

Usage

pip install pypinyin
python analyze_relaxed.py

Global Perspective

Checked international metro systems (Tokyo, Seoul, Taipei, Hong Kong):

• Japanese stations use kanji+kana, theoretically possible but rare
• Korean syllable blocks reversed usually don't form words
• Latin alphabet systems almost impossible

Guangzhou Line 6's 河沙↔沙河 may be the only example globally.

Guangzhou Line 6 Fun Fact

Called "China's metro line with highest sand content": 横沙 → 沙贝 → 河沙 → 黄沙 → ... → 沙河顶 → 沙河

6 stations with 沙 (sand)! In Cantonese geography, 沙 represents small islands formed by river sediment.

License

MIT

Links

• Zhihu Question
• snolab