Merge pull request #845 from alexwlchan/more-tils

Add a TIL that didn't get migrated across properly

src/_til/2024/2024-01-19-offline-geo-lookups-of-ip-addresses.md

@@ -0,0 +1,49 @@
+---
+layout: til
+title: How to do offline geo-lookups of IP addresses
+summary: |
+  MaxMind offer databases you can do to look up IP addresses without sending the address off to a remote service.
+date: 2024-01-19 10:25:34 +0000
+tags:
+  - python
+  - networking
+---
+I was experimenting with web analytics, and I wanted a way to look up the country for an IP address -- in a privacy-preserving way.
+
+There are lots of web APIs for doing IP address lookup, e.g.
+
+```console
+$ curl "https://api.ipregistry.co/1.2.3.4?key=tryout"
+```
+
+These are suitable for certain one-off tasks, but you're sending the IP address off to a third-party service.
+If I use this in an analytics package, I'm handing a complete list of visitor addresses to this service.
+Ick!
+
+(Plus making an HTTP request for each IP address probably introduces lots of latency.)
+
+A [Stack Overflow answer][so] pointed me at [MaxMind].
+I was able to download a free country database from their site, which is about 6.4MB in "MaxMind DB" format -- a [database format][mmdb] designed for fast IP address lookups.
+
+I can then use [the maxminddb Python library][maxminddb] to open the database and look up IP addresses:
+
+```python
+import maxminddb
+
+with maxminddb.open_database('GeoLite2-Country_20240116/GeoLite2-Country.mmdb') as reader:
+    print(reader.get('52.85.118.55'))
+    # {'continent': {'code': 'NA', 'geoname_id': 6255149, …
+```
+
+Note that this method can sometimes return `None`, if the IP address isn't in the database -- or in this case, if it's an IP address reserved for testing purposes.
+
+```python
+with maxminddb.open_database('GeoLite2-Country_20240116/GeoLite2-Country.mmdb') as reader:
+    print(reader.get('192.0.2.0'))
+    # None
+```
+
+[so]: https://stackoverflow.com/q/17182203/1558022
+[MaxMind]: https://www.maxmind.com/en/home
+[mmdb]: https://maxmind.github.io/MaxMind-DB/
+[maxminddb]: https://pypi.org/project/maxminddb/

src/_til/2024/2024-02-21-what-happens-when-you-replace-a-photo.md

@@ -1,7 +1,7 @@
 ---
 layout: til
 date: 2024-02-21 12:33:15 +0000
-title: What happens when you replace a photo?
+title: What happens when you replace a photo on Flickr?
 tags:
   - flickr
 ---
@@ -32,7 +32,7 @@ Here's an example from one of my photos, using the flickr.photos.getInfo API:
 ```
 
 Note that this also bumps the `lastupdate` attribute in the `<dates>` element, e.g.:
-  
+
 ```diff
  <dates
    posted="1707315985"