OSM housenumbers ending in "a" vs "b"/"c"/"d"/"e"/"f"

count_housenumber_letters.sh

#!/bin/sh
# first step takes about 1h 45m on my 4core VM and produces about 300MB output file. The second step is about 2.5m 
# it counts housenumbers ending in a number and a single letter (e.g. '42b') and outputs frequency of those letters a-f
# for testing https://github.com/streetcomplete/StreetComplete/issues/5479#issuecomment-1937812748

time pv -ptebar planet-240205.osm.bz2 | pbzip2 -dc | ag -F 'addr:housenumber' | zstd > housenumbers.xml.zstd
time pv housenumbers.xml.zstd | zstdmt -dc | perl -nE 'if (/^\s*<tag k="addr:housenumber"\sv="(.*?)\s*".*$/) { $n=$1; $a++ if $n=~/\da$/i; $b++ if $n=~/\db$/i; $c++ if $n=~/\dc$/i;  $d++ if $n=~/\dd$/i;  $e++ if $n=~/\de$/i;  $f++ if $n=~/\df$/i;} END { say "a=$a\nb=$b\nc=$c\nd=$d\ne=$e\nf=$f\n" }'

# result:
#a=4593803
#b=1862098
#c=756913
#d=435247
#e=251648
#f=167140