Remove socket.inet_pton (#318)

Closes #317.

- Remove **socket.inet_pton** which does not reject IPv4 addresses and IPv6 (dual) addresses with leading IPv4 zeroes on macOS.
- Add **test_looks_like_ipv6**

.github/workflows/ci.yml

@@ -32,6 +32,7 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.language.python-version }}
+          check-latest: true
       - name: Install Python requirements
         run: |
           pip install --upgrade pip

tests/main_test.py

@@ -4,6 +4,7 @@
 
 import logging
 import os
+import sys
 import tempfile
 from collections.abc import Sequence
 from pathlib import Path
@@ -17,7 +18,7 @@
 import tldextract
 import tldextract.suffix_list
 from tldextract.cache import DiskCache
-from tldextract.remote import inet_pton, lenient_netloc, looks_like_ip
+from tldextract.remote import lenient_netloc, looks_like_ip, looks_like_ipv6
 from tldextract.suffix_list import SuffixListNotFound
 from tldextract.tldextract import ExtractResult
 
@@ -152,21 +153,24 @@ def test_lenient_netloc() -> None:
     )
 
 
-@pytest.mark.skipif(not inet_pton, reason="inet_pton unavailable")
-def test_looks_like_ip_with_inet_pton() -> None:
-    """Test preferred function to check if a string looks like an IP address."""
-    assert looks_like_ip("1.1.1.1", inet_pton) is True
-    assert looks_like_ip("a.1.1.1", inet_pton) is False
-    assert looks_like_ip("1.1.1.1\n", inet_pton) is False
-    assert looks_like_ip("256.256.256.256", inet_pton) is False
+def test_looks_like_ip() -> None:
+    """Test function to check if a string looks like an IPv4 address."""
+    assert looks_like_ip("1.1.1.1") is True
+    assert looks_like_ip("1.1.1.01") is False
+    assert looks_like_ip("a.1.1.1") is False
+    assert looks_like_ip("1.1.1.1\n") is False
+    assert looks_like_ip("256.256.256.256") is False
 
 
-def test_looks_like_ip_without_inet_pton() -> None:
-    """Test fallback function to check if a string looks like an IP address."""
-    assert looks_like_ip("1.1.1.1", None) is True
-    assert looks_like_ip("a.1.1.1", None) is False
-    assert looks_like_ip("1.1.1.1\n", None) is False
-    assert looks_like_ip("256.256.256.256", None) is False
+def test_looks_like_ipv6() -> None:
+    """Test function to check if a string looks like an IPv6 address."""
+    assert looks_like_ipv6("::") is True
+    assert looks_like_ipv6("aBcD:ef01:2345:6789:aBcD:ef01:aaaa:2288") is True
+    assert looks_like_ipv6("aBcD:ef01:2345:6789:aBcD:ef01:127.0.0.1") is True
+    assert looks_like_ipv6("ZBcD:ef01:2345:6789:aBcD:ef01:127.0.0.1") is False
+    if sys.version_info >= (3, 8, 12):  # noqa: UP036
+        assert looks_like_ipv6("aBcD:ef01:2345:6789:aBcD:ef01:127.0.0.01") is False
+    assert looks_like_ipv6("aBcD:ef01:2345:6789:aBcD:") is False
 
 
 def test_similar_to_ip() -> None:

tldextract/cache.py

@@ -38,8 +38,7 @@ def md5(*args: bytes) -> hashlib._Hash:
 
 
 def get_pkg_unique_identifier() -> str:
-    """
-    Generate an identifier unique to the python version, tldextract version, and python instance.
+    """Generate an identifier unique to the python version, tldextract version, and python instance.
 
     This will prevent interference between virtualenvs and issues that might arise when installing
     a new version of tldextract
@@ -66,8 +65,7 @@ def get_pkg_unique_identifier() -> str:
 
 
 def get_cache_dir() -> str:
-    """
-    Get a cache dir that we have permission to write to.
+    """Get a cache dir that we have permission to write to.
 
     Try to follow the XDG standard, but if that doesn't work fallback to the package directory
     http://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html

tldextract/remote.py

@@ -3,16 +3,9 @@
 from __future__ import annotations
 
 import re
-from collections.abc import Callable
 from ipaddress import AddressValueError, IPv6Address
 from urllib.parse import scheme_chars
 
-inet_pton: Callable[[int, str], bytes] | None
-try:
-    from socket import AF_INET, AF_INET6, inet_pton  # Availability: Unix, Windows.
-except ImportError:
-    inet_pton = None
-
 IP_RE = re.compile(
     r"^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.)"
     r"{3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
@@ -59,32 +52,16 @@ def _schemeless_url(url: str) -> str:
     return url[double_slashes_start + 2 :]
 
 
-def looks_like_ip(
-    maybe_ip: str, pton: Callable[[int, str], bytes] | None = inet_pton
-) -> bool:
-    """Check whether the given str looks like an IP address."""
+def looks_like_ip(maybe_ip: str) -> bool:
+    """Check whether the given str looks like an IPv4 address."""
     if not maybe_ip[0].isdigit():
         return False
 
-    if pton is not None:
-        try:
-            pton(AF_INET, maybe_ip)
-            return True
-        except OSError:
-            return False
     return IP_RE.fullmatch(maybe_ip) is not None
 
 
-def looks_like_ipv6(
-    maybe_ip: str, pton: Callable[[int, str], bytes] | None = inet_pton
-) -> bool:
+def looks_like_ipv6(maybe_ip: str) -> bool:
     """Check whether the given str looks like an IPv6 address."""
-    if pton is not None:
-        try:
-            pton(AF_INET6, maybe_ip)
-            return True
-        except OSError:
-            return False
     try:
         IPv6Address(maybe_ip)
     except AddressValueError:

tldextract/tldextract.py

@@ -75,8 +75,7 @@ class ExtractResult:
 
     @property
     def registered_domain(self) -> str:
-        """
-        Joins the domain and suffix fields with a dot, if they're both set.
+        """Joins the domain and suffix fields with a dot, if they're both set.
 
         >>> extract('http://forums.bbc.co.uk').registered_domain
         'bbc.co.uk'
@@ -89,8 +88,7 @@ def registered_domain(self) -> str:
 
     @property
     def fqdn(self) -> str:
-        """
-        Returns a Fully Qualified Domain Name, if there is a proper domain/suffix.
+        """Returns a Fully Qualified Domain Name, if there is a proper domain/suffix.
 
         >>> extract('http://forums.bbc.co.uk/path/to/file').fqdn
         'forums.bbc.co.uk'
@@ -103,8 +101,7 @@ def fqdn(self) -> str:
 
     @property
     def ipv4(self) -> str:
-        """
-        Returns the ipv4 if that is what the presented domain/url is.
+        """Returns the ipv4 if that is what the presented domain/url is.
 
         >>> extract('http://127.0.0.1/path/to/file').ipv4
         '127.0.0.1'
@@ -123,8 +120,7 @@ def ipv4(self) -> str:
 
     @property
     def ipv6(self) -> str:
-        """
-        Returns the ipv6 if that is what the presented domain/url is.
+        """Returns the ipv6 if that is what the presented domain/url is.
 
         >>> extract('http://[aBcD:ef01:2345:6789:aBcD:ef01:127.0.0.1]/path/to/file').ipv6
         'aBcD:ef01:2345:6789:aBcD:ef01:127.0.0.1'
@@ -334,8 +330,7 @@ def update(
 
     @property
     def tlds(self, session: requests.Session | None = None) -> list[str]:
-        """
-        Returns the list of tld's used by default.
+        """Returns the list of tld's used by default.
 
         This will vary based on `include_psl_private_domains` and `extra_suffixes`
         """