FA-95901 / Postal address normalization / Open access
Five-or-nine digit postal code: space-separated plus-four is rejected · case 01
"12029 4101" returns None although a space separator is allowed.
ROOT CAUSE
Only a hyphen is accepted at index 5.
VERIFIED REPAIR
Accept exactly a hyphen or a space at index 5.
Unsuccessful approach: Accepting any non-digit at index 5 also turns "12029/4101" into a valid code.
Case contract
Input a string or an integer. Integers are zero-padded to 5 digits when <= 99999, else to 9. Strings are stripped; a 10-character string with "-" or a space at index 5 loses that separator. Valid results are exactly 5 or 9 ASCII digits; 9 digits render "DDDDD-DDDD" unless the last four are "0000", which renders the 5-digit form. Anything else returns None.
Why this case matters
Postal codes arrive from spreadsheets, forms and legacy files; losing leading zeros or accepting malformed codes misroutes mail and breaks deduplication.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(x):
if isinstance(x, int):
s = str(x).zfill(5) if x <= 99999 else str(x).zfill(9)
else:
s = x.strip()
if len(s) == 10 and s[5] == '-':
s = s[:5] + s[6:]
if len(s) not in (5, 9) or not s.isdigit():
return None
if len(s) == 9 and s[5:] != '0000':
return s[:5] + '-' + s[5:]
return s[:5]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['plain five-digit code', '12039', '12039'], ['hyphenated plus-four', '12039-4101', '12039-4101'], ['space-separated plus-four', '12039 4101', '12039-4101'], ['spreadsheet integer lost its leading zero', 1231, '01231'], ['eight-digit integer is a nine-digit code with a leading zero', 12345671, '01234-5671'], ['zero plus-four is dropped', '12039-0000', '12039'], ['plus-four ending in three zeros is kept', '12039-2000', '12039-2000'], ['seven digits rejected', '1203912', None], ['ten digits without separator rejected', '1203941017', None], ['slash separator rejected', '12039/4101', None], ['letter O is not zero', '1203O', None], ['surrounding whitespace trimmed', ' 12039\n', '12039']], [['plain five-digit code', '23049', '23049'], ['hyphenated plus-four', '23049-5102', '23049-5102'], ['space-separated plus-four', '23049 5102', '23049-5102'], ['spreadsheet integer lost its leading zero', 1232, '01232'], ['eight-digit integer is a nine-digit code with a leading zero', 12345672, '01234-5672'], ['zero plus-four is dropped', '23049-0000', '23049'], ['plus-four ending in three zeros is kept', '23049-3000', '23049-3000'], ['seven digits rejected', '2304912', None], ['ten digits without separator rejected', '2304951027', None], ['slash separator rejected', '23049/5102', None], ['letter O is not zero', '2304O', None], ['surrounding whitespace trimmed', ' 23049\n', '23049']], [['plain five-digit code', '34059', '34059'], ['hyphenated plus-four', '34059-6103', '34059-6103'], ['space-separated plus-four', '34059 6103', '34059-6103'], ['spreadsheet integer lost its leading zero', 1233, '01233'], ['eight-digit integer is a nine-digit code with a leading zero', 12345673, '01234-5673'], ['zero plus-four is dropped', '34059-0000', '34059'], ['plus-four ending in three zeros is kept', '34059-4000', '34059-4000'], ['seven digits rejected', '3405912', None], ['ten digits without separator rejected', '3405961037', None], ['slash separator rejected', '34059/6103', None], ['letter O is not zero', '3405O', None], ['surrounding whitespace trimmed', ' 34059\n', '34059']], [['plain five-digit code', '45069', '45069'], ['hyphenated plus-four', '45069-7104', '45069-7104'], ['space-separated plus-four', '45069 7104', '45069-7104'], ['spreadsheet integer lost its leading zero', 1234, '01234'], ['eight-digit integer is a nine-digit code with a leading zero', 12345674, '01234-5674'], ['zero plus-four is dropped', '45069-0000', '45069'], ['plus-four ending in three zeros is kept', '45069-5000', '45069-5000'], ['seven digits rejected', '4506912', None], ['ten digits without separator rejected', '4506971047', None], ['slash separator rejected', '45069/7104', None], ['letter O is not zero', '4506O', None], ['surrounding whitespace trimmed', ' 45069\n', '45069']], [['plain five-digit code', '56079', '56079'], ['hyphenated plus-four', '56079-8105', '56079-8105'], ['space-separated plus-four', '56079 8105', '56079-8105'], ['spreadsheet integer lost its leading zero', 1235, '01235'], ['eight-digit integer is a nine-digit code with a leading zero', 12345675, '01234-5675'], ['zero plus-four is dropped', '56079-0000', '56079'], ['plus-four ending in three zeros is kept', '56079-6000', '56079-6000'], ['seven digits rejected', '5607912', None], ['ten digits without separator rejected', '5607981057', None], ['slash separator rejected', '56079/8105', None], ['letter O is not zero', '5607O', None], ['surrounding whitespace trimmed', ' 56079\n', '56079']]]
for label, arg, expected in fixtures[N - 1]:
check(label, solve(arg), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| plain five-digit code | 12039 | 12039 | Passed |
| hyphenated plus-four | 12039-4101 | 12039-4101 | Passed |
| space-separated plus-four | None | 12039-4101 | Failed |
| spreadsheet integer lost its leading zero | 01231 | 01231 | Passed |
| eight-digit integer is a nine-digit code with a leading zero | 01234-5671 | 01234-5671 | Passed |
| zero plus-four is dropped | 12039 | 12039 | Passed |
| plus-four ending in three zeros is kept | 12039-2000 | 12039-2000 | Passed |
| seven digits rejected | None | None | Passed |
| ten digits without separator rejected | None | None | Passed |
| slash separator rejected | None | None | Passed |
| letter O is not zero | None | None | Passed |
| surrounding whitespace trimmed | 12039 | 12039 | Passed |
SHA-256 / 58ec59e6a09987062b5ca5d8ea6a754f0117f768a1ebf8f4f3f4b291c383ad94
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(x):
if isinstance(x, int):
s = str(x).zfill(5) if x <= 99999 else str(x).zfill(9)
else:
s = x.strip()
if len(s) == 10 and not s[5].isdigit():
s = s[:5] + s[6:]
if len(s) not in (5, 9) or not s.isdigit():
return None
if len(s) == 9 and s[5:] != '0000':
return s[:5] + '-' + s[5:]
return s[:5]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['plain five-digit code', '12039', '12039'], ['hyphenated plus-four', '12039-4101', '12039-4101'], ['space-separated plus-four', '12039 4101', '12039-4101'], ['spreadsheet integer lost its leading zero', 1231, '01231'], ['eight-digit integer is a nine-digit code with a leading zero', 12345671, '01234-5671'], ['zero plus-four is dropped', '12039-0000', '12039'], ['plus-four ending in three zeros is kept', '12039-2000', '12039-2000'], ['seven digits rejected', '1203912', None], ['ten digits without separator rejected', '1203941017', None], ['slash separator rejected', '12039/4101', None], ['letter O is not zero', '1203O', None], ['surrounding whitespace trimmed', ' 12039\n', '12039']], [['plain five-digit code', '23049', '23049'], ['hyphenated plus-four', '23049-5102', '23049-5102'], ['space-separated plus-four', '23049 5102', '23049-5102'], ['spreadsheet integer lost its leading zero', 1232, '01232'], ['eight-digit integer is a nine-digit code with a leading zero', 12345672, '01234-5672'], ['zero plus-four is dropped', '23049-0000', '23049'], ['plus-four ending in three zeros is kept', '23049-3000', '23049-3000'], ['seven digits rejected', '2304912', None], ['ten digits without separator rejected', '2304951027', None], ['slash separator rejected', '23049/5102', None], ['letter O is not zero', '2304O', None], ['surrounding whitespace trimmed', ' 23049\n', '23049']], [['plain five-digit code', '34059', '34059'], ['hyphenated plus-four', '34059-6103', '34059-6103'], ['space-separated plus-four', '34059 6103', '34059-6103'], ['spreadsheet integer lost its leading zero', 1233, '01233'], ['eight-digit integer is a nine-digit code with a leading zero', 12345673, '01234-5673'], ['zero plus-four is dropped', '34059-0000', '34059'], ['plus-four ending in three zeros is kept', '34059-4000', '34059-4000'], ['seven digits rejected', '3405912', None], ['ten digits without separator rejected', '3405961037', None], ['slash separator rejected', '34059/6103', None], ['letter O is not zero', '3405O', None], ['surrounding whitespace trimmed', ' 34059\n', '34059']], [['plain five-digit code', '45069', '45069'], ['hyphenated plus-four', '45069-7104', '45069-7104'], ['space-separated plus-four', '45069 7104', '45069-7104'], ['spreadsheet integer lost its leading zero', 1234, '01234'], ['eight-digit integer is a nine-digit code with a leading zero', 12345674, '01234-5674'], ['zero plus-four is dropped', '45069-0000', '45069'], ['plus-four ending in three zeros is kept', '45069-5000', '45069-5000'], ['seven digits rejected', '4506912', None], ['ten digits without separator rejected', '4506971047', None], ['slash separator rejected', '45069/7104', None], ['letter O is not zero', '4506O', None], ['surrounding whitespace trimmed', ' 45069\n', '45069']], [['plain five-digit code', '56079', '56079'], ['hyphenated plus-four', '56079-8105', '56079-8105'], ['space-separated plus-four', '56079 8105', '56079-8105'], ['spreadsheet integer lost its leading zero', 1235, '01235'], ['eight-digit integer is a nine-digit code with a leading zero', 12345675, '01234-5675'], ['zero plus-four is dropped', '56079-0000', '56079'], ['plus-four ending in three zeros is kept', '56079-6000', '56079-6000'], ['seven digits rejected', '5607912', None], ['ten digits without separator rejected', '5607981057', None], ['slash separator rejected', '56079/8105', None], ['letter O is not zero', '5607O', None], ['surrounding whitespace trimmed', ' 56079\n', '56079']]]
for label, arg, expected in fixtures[N - 1]:
check(label, solve(arg), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| plain five-digit code | 12039 | 12039 | Passed |
| hyphenated plus-four | 12039-4101 | 12039-4101 | Passed |
| space-separated plus-four | 12039-4101 | 12039-4101 | Passed |
| spreadsheet integer lost its leading zero | 01231 | 01231 | Passed |
| eight-digit integer is a nine-digit code with a leading zero | 01234-5671 | 01234-5671 | Passed |
| zero plus-four is dropped | 12039 | 12039 | Passed |
| plus-four ending in three zeros is kept | 12039-2000 | 12039-2000 | Passed |
| seven digits rejected | None | None | Passed |
| ten digits without separator rejected | None | None | Passed |
| slash separator rejected | 12039-4101 | None | Failed |
| letter O is not zero | None | None | Passed |
| surrounding whitespace trimmed | 12039 | 12039 | Passed |
SHA-256 / 318ca8a249bfee42d04b836d452b9f50930c9342392ea794e96b1f96fbd978b8
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(x):
if isinstance(x, int):
s = str(x).zfill(5) if x <= 99999 else str(x).zfill(9)
else:
s = x.strip()
if len(s) == 10 and s[5] in '- ':
s = s[:5] + s[6:]
if len(s) not in (5, 9) or not s.isdigit():
return None
if len(s) == 9 and s[5:] != '0000':
return s[:5] + '-' + s[5:]
return s[:5]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['plain five-digit code', '12039', '12039'], ['hyphenated plus-four', '12039-4101', '12039-4101'], ['space-separated plus-four', '12039 4101', '12039-4101'], ['spreadsheet integer lost its leading zero', 1231, '01231'], ['eight-digit integer is a nine-digit code with a leading zero', 12345671, '01234-5671'], ['zero plus-four is dropped', '12039-0000', '12039'], ['plus-four ending in three zeros is kept', '12039-2000', '12039-2000'], ['seven digits rejected', '1203912', None], ['ten digits without separator rejected', '1203941017', None], ['slash separator rejected', '12039/4101', None], ['letter O is not zero', '1203O', None], ['surrounding whitespace trimmed', ' 12039\n', '12039']], [['plain five-digit code', '23049', '23049'], ['hyphenated plus-four', '23049-5102', '23049-5102'], ['space-separated plus-four', '23049 5102', '23049-5102'], ['spreadsheet integer lost its leading zero', 1232, '01232'], ['eight-digit integer is a nine-digit code with a leading zero', 12345672, '01234-5672'], ['zero plus-four is dropped', '23049-0000', '23049'], ['plus-four ending in three zeros is kept', '23049-3000', '23049-3000'], ['seven digits rejected', '2304912', None], ['ten digits without separator rejected', '2304951027', None], ['slash separator rejected', '23049/5102', None], ['letter O is not zero', '2304O', None], ['surrounding whitespace trimmed', ' 23049\n', '23049']], [['plain five-digit code', '34059', '34059'], ['hyphenated plus-four', '34059-6103', '34059-6103'], ['space-separated plus-four', '34059 6103', '34059-6103'], ['spreadsheet integer lost its leading zero', 1233, '01233'], ['eight-digit integer is a nine-digit code with a leading zero', 12345673, '01234-5673'], ['zero plus-four is dropped', '34059-0000', '34059'], ['plus-four ending in three zeros is kept', '34059-4000', '34059-4000'], ['seven digits rejected', '3405912', None], ['ten digits without separator rejected', '3405961037', None], ['slash separator rejected', '34059/6103', None], ['letter O is not zero', '3405O', None], ['surrounding whitespace trimmed', ' 34059\n', '34059']], [['plain five-digit code', '45069', '45069'], ['hyphenated plus-four', '45069-7104', '45069-7104'], ['space-separated plus-four', '45069 7104', '45069-7104'], ['spreadsheet integer lost its leading zero', 1234, '01234'], ['eight-digit integer is a nine-digit code with a leading zero', 12345674, '01234-5674'], ['zero plus-four is dropped', '45069-0000', '45069'], ['plus-four ending in three zeros is kept', '45069-5000', '45069-5000'], ['seven digits rejected', '4506912', None], ['ten digits without separator rejected', '4506971047', None], ['slash separator rejected', '45069/7104', None], ['letter O is not zero', '4506O', None], ['surrounding whitespace trimmed', ' 45069\n', '45069']], [['plain five-digit code', '56079', '56079'], ['hyphenated plus-four', '56079-8105', '56079-8105'], ['space-separated plus-four', '56079 8105', '56079-8105'], ['spreadsheet integer lost its leading zero', 1235, '01235'], ['eight-digit integer is a nine-digit code with a leading zero', 12345675, '01234-5675'], ['zero plus-four is dropped', '56079-0000', '56079'], ['plus-four ending in three zeros is kept', '56079-6000', '56079-6000'], ['seven digits rejected', '5607912', None], ['ten digits without separator rejected', '5607981057', None], ['slash separator rejected', '56079/8105', None], ['letter O is not zero', '5607O', None], ['surrounding whitespace trimmed', ' 56079\n', '56079']]]
for label, arg, expected in fixtures[N - 1]:
check(label, solve(arg), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| plain five-digit code | 12039 | 12039 | Passed |
| hyphenated plus-four | 12039-4101 | 12039-4101 | Passed |
| space-separated plus-four | 12039-4101 | 12039-4101 | Passed |
| spreadsheet integer lost its leading zero | 01231 | 01231 | Passed |
| eight-digit integer is a nine-digit code with a leading zero | 01234-5671 | 01234-5671 | Passed |
| zero plus-four is dropped | 12039 | 12039 | Passed |
| plus-four ending in three zeros is kept | 12039-2000 | 12039-2000 | Passed |
| seven digits rejected | None | None | Passed |
| ten digits without separator rejected | None | None | Passed |
| slash separator rejected | None | None | Passed |
| letter O is not zero | None | None | Passed |
| surrounding whitespace trimmed | 12039 | 12039 | Passed |
SHA-256 / c32795b8a0f49bfd0ad869ca6928cdd31471271c1cfa784b88444a76fd3d1495
Verification & scope
A deterministic toy contract over synthetic, obviously fictitious addresses. The rules are stipulated for this model only and make no claim of conformance with any postal authority standard. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.
Observations recorded using Python 3.12.14 at 2026-09-29T14:52:17.959212+00:00.
Case digest / 3bdaea690772b7cadb104bbbded3519b74516a94565530b3ede5abd4fea45243