CW222222+22 python decode reject but C and google maps say 70,180

[wblangdon]

The Python version of decode treats some edge cases
differently from other implementations, for example C and google maps.

For example openlocationcode.py olc.decode('CW222222+22') gives
~/.local/lib/python3.11/site-packages/openlocationcode/openlocationcode.py", line 341, in decode
raise ValueError(
ValueError: Passed Open Location Code is not a valid full code - CW222222+22

Whereas C:
with argv[1] as CW222222+22
OLC_CodeArea code_area;
OLC_Decode(argv[1], 0, &code_area);
printf("%.18f,%.18f\n",code_area.lo.lat, code_area.lo.lon);
gives: 70.000000000000000000,180.000000000000000000

Similarly google maps accepts CW222222+22
(and appears to convert it to C2222222+22)

Python 3.11.5
gcc version 11.5.0
Linux Rocky 9

google maps Ubuntu Firefox 149.0.2

Bill

[karineek]

I managed to reproduce this error, creating these two drivers, in Python:

from openlocationcode import openlocationcode as olc

code = "CW222222+22"

print("Testing:", code)

try:
    area = olc.decode(code)
    print("decoded successfully")
    print("latLo:", area.latitudeLo)
    print("lngLo:", area.longitudeLo)
    print("latHi:", area.latitudeHi)
    print("lngHi:", area.longitudeHi)
except Exception as e:
    print(type(e).__name__ + ":", e)

which outputs:

Testing: CW222222+22
ValueError: Passed Open Location Code is not a valid full code - CW222222+22

or without the exception handler, we get:

Traceback (most recent call last):
  File "/users/kevenmen/open-location-code/../test_decode.py", line 8, in <module>
    area = olc.decode(code)
  File "/users/kevenmen/.local/lib/python3.10/site-packages/openlocationcode/openlocationcode.py", line 320, in decode
    raise ValueError(
ValueError: Passed Open Location Code is not a valid full code - CW222222+22

and then in C:

#include <stdio.h>
#include "c/src/olc.h"

int main(void) {
    OLC_CodeArea code_area;

    OLC_Decode("CW222222+22", 0, &code_area);

    printf("lo.lat = %.18f\n", code_area.lo.lat);
    printf("lo.lon = %.18f\n", code_area.lo.lon);
    printf("hi.lat = %.18f\n", code_area.hi.lat);
    printf("hi.lon = %.18f\n", code_area.hi.lon);
    printf("len    = %lu\n", code_area.len);

    return 0;
}

which then I get:

lo.lat = 70.000000000000000000
lo.lon = 180.000000000000000000
hi.lat = 70.000124999999997044
hi.lon = 180.000124999999997044
len    = 10

Versions:

C code: commit 83986da0156bbf51fba33d0327d8ca4b7f955c89
Python code:

kevenmen@node0:~/open-location-code$ python3 -m pip show openlocationcode
Name: openlocationcode
Version: 1.0.1
Summary: Python library for Open Location Code (Plus Codes)
Home-page: https://github.com/google/open-location-code
Author: Google
Author-email: open-location-code@googlegroups.com
License: Apache 2.0
Location: /users/kevenmen/.local/lib/python3.10/site-packages
Requires: 
Required-by: 

and the system:

kevenmen@node0:~/open-location-code$ python3 --version
Python 3.10.12
kevenmen@node0:~/open-location-code$ gcc --version
gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0
Copyright (C) 2021 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

kevenmen@node0:~/open-location-code$ 

System: x86_64

[wblangdon]

The basic difference is the C code, functions analyse() and decode(),
include many sanity checks but these do not include range checks on lat,lon.
Whereas openlocationcode.py isFull() includes checks
if firstLatValue >= LATITUDE_MAX_ * 2:
if firstLngValue >= LONGITUDE_MAX_ * 2: