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Revise Taipei 101 geocoding details #25

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Revise Taipei 101 geocoding details #25

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84 changes: 48 additions & 36 deletions week05/lectures/week05_lecture.md
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Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,7 @@ In real-world programming, you rarely work with clean, predictable data. APIs re
**Geocoding** is the process of converting human-readable addresses or place names into geographic coordinates (latitude and longitude).

```
┌─────────────────────────┐ Geocoding ┌─────────────────────┐
┌─────────────────────────┐ Geocoding ┌─────────────────────┐
│ "Taipei 101" │ ──────────────────> │ (25.0339, 121.5645) │
│ (Place Name) │ │ (Coordinates) │
└─────────────────────────┘ └─────────────────────┘
Expand Down Expand Up @@ -292,20 +292,20 @@ When you make a search request, Nominatim returns a **list of place objects**. L
```json
[
{
"place_id": 297611768,
"place_id": 424937126,
"licence": "Data © OpenStreetMap contributors...",
"osm_type": "way",
"osm_id": 55284753,
"lat": "25.0339639",
"lon": "121.5644722",
"class": "tourism",
"osm_id": 1159328965,
"lat": "25.0338352",
"lon": "121.5644995",
"class": "building",
"type": "attraction",
"place_rank": 30,
"importance": 0.6864891756640247,
"addresstype": "tourism",
"importance": 0.5453714025007607,
"addresstype": "building",
"name": "台北101",
"display_name": "台北101, 7, Section 5, Xinyi Road, Xinyi District, Taipei, 110, Taiwan",
"boundingbox": ["25.0329639", "25.0349639", "121.5634722", "121.5654722"]
"display_name": "台北101, 7, 信義路五段, 西村里, 信義區, 信義商圈, 臺北市, 11049, 臺灣",
"boundingbox": ["25.0332803", "25.0346102", "121.5638583", "121.5652356"]
}
]
```
Expand All @@ -318,8 +318,8 @@ Let's understand what each field means:

| Field | Type | Description | Example |
|-------|------|-------------|---------|
| `place_id` | int | Unique ID in Nominatim's database | `297611768` |
| `osm_id` | int | ID in OpenStreetMap database | `55284753` |
| `place_id` | int | Unique ID in Nominatim's database | `424937126` |
| `osm_id` | int | ID in OpenStreetMap database | `1159328965` |
| `osm_type` | string | Type in OSM | `"way"` |

**Understanding `osm_type`**:
Expand Down Expand Up @@ -371,8 +371,8 @@ float(result["lat"]) + 1 # Works: 26.0339639

**Understanding `importance`**:
- Higher = more famous/notable
- Eiffel Tower: ~0.8
- Taipei 101: ~0.68
- Eiffel Tower: ~0.62
- Taipei 101: ~0.55
- Local coffee shop: ~0.2

**Understanding `place_rank`**:
Expand All @@ -390,7 +390,7 @@ float(result["lat"]) + 1 # Works: 26.0339639

```python
result["name"] # "台北101"
result["display_name"] # "台北101, 7, Section 5, Xinyi Road, Xinyi District, Taipei, 110, Taiwan"
result["display_name"] # "台北101, 7, 信義路五段, 西村里, 信義區, 信義商圈, 臺北市, 11049, 臺灣"
```

---
Expand Down Expand Up @@ -493,15 +493,18 @@ The response includes a nested `address` object with structured information:
{
"lat": "25.0339639",
"lon": "121.5644722",
"display_name": "台北101, 7, Section 5, Xinyi Road, ...",
"display_name": "台北101, 7, 信義路五段, 西村里, 信義區, 信義商圈, 臺北市, 11049, 臺灣",
"address": {
"tourism": "台北101",
"house_number": "7",
"road": "Section 5, Xinyi Road",
"suburb": "Xinyi District",
"city": "Taipei",
"postcode": "110",
"country": "Taiwan",
"road": "信義路五段",
"neighbourhood": "西村里",
"suburb": "信義區",
"village": "信義商圈",
"city": "臺北市",
"ISO3166-2-lvl4": "TW-TPE",
"postcode": "11049",
"country": "臺灣",
"country_code": "tw"
}
}
Expand All @@ -514,12 +517,17 @@ The `address` object contains **components** of the address, but the keys vary d
**For a tourist attraction (Taipei 101)**:
```json
{
"tourism": "台北101", // The name, keyed by class
"tourism": "台北101",
"house_number": "7",
"road": "Section 5, Xinyi Road",
"suburb": "Xinyi District", // District/neighborhood
"city": "Taipei",
"country": "Taiwan"
"road": "信義路五段",
"neighbourhood": "西村里",
"suburb": "信義區",
"village": "信義商圈",
"city": "臺北市", // with city, villge, suburb
"ISO3166-2-lvl4": "TW-TPE",
"postcode": "11049",
"country": "臺灣",
"country_code": "tw"
}
```

Expand Down Expand Up @@ -606,18 +614,22 @@ Here are two real Nominatim responses showing how different they can be:
# Response for "Taipei 101" - a major landmark
{
"name": "台北101",
"display_name": "台北101, 7, Section 5, Xinyi Road, Xinyi District, Taipei, Taiwan",
"display_name": "台北101, 7, 信義路五段, 西村里, 信義區, 信義商圈, 臺北市, 11049, 臺灣'",
"address": {
"tourism": "台北101",
"house_number": "7",
"road": "Section 5, Xinyi Road",
"suburb": "Xinyi District",
"city": "Taipei",
"postcode": "110",
"country": "Taiwan",
"road": "信義路五段",
"neighbourhood": "西村里",
"suburb": "信義區",
"village": "信義商圈",
"city": "臺北市",
"ISO3166-2-lvl4": "TW-TPE",
"postcode": "11049",
"country": "臺灣",
"country_code": "tw"
},
"importance": 0.68
"importance": 0.55
...
}

# Response for a small village - much sparser
Expand Down Expand Up @@ -856,7 +868,7 @@ Now with a missing key:
```python
# Raw Nominatim response
result = {
"lat": "25.0339",
"lat": "25.0338",
"lon": "121.5645",
"display_name": "Taipei 101, Taipei, Taiwan",
"address": {
Expand Down Expand Up @@ -1870,8 +1882,8 @@ Enter a place name, or 'quit' to exit.
geocoder> Taipei 101

Name: 台北101
Coordinates: (25.033964, 121.564472)
Address: 台北101, 7, Section 5, Xinyi Road, Xinyi District, Taipei, Taiwan
Coordinates: (25.033835, 121.564499)
Address: 台北101, 7, 信義路五段, 西村里, 信義區, 信義商圈, 臺北市, 11049, 臺灣

geocoder> xyznotaplace
No results for: xyznotaplace
Expand Down