drop support for Python 2.x as it is very much EOL

A follow-up to b96a5ad where we stopped
having CI run tests on Python 2.x. This actually drops the few remaining
Python 2.x compatibility bits and drops support for it as it's long
EOL'd.

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

examples/menuconfig_example.py

@@ -130,11 +130,6 @@
                        TRI_TO_STR
 
 
-# Python 2/3 compatibility hack
-if sys.version_info[0] < 3:
-    input = raw_input
-
-
 def indent_print(s, indent):
     print(indent*" " + s)
 

kconfiglib.py

@@ -3926,8 +3926,7 @@ def _open(self, filename, mode):
         # - For Python 3, force the encoding. Forcing the encoding on Python 2
         #   turns strings into Unicode strings, which gets messy. Python 2
         #   doesn't decode regular strings anyway.
-        return open(filename, "rU" if mode == "r" else mode) if _IS_PY2 else \
-               open(filename, mode, encoding=self._encoding)
+        return open(filename, mode, encoding=self._encoding)
 
     def _check_undef_syms(self):
         # Prints warnings for all references to undefined symbols within the
@@ -3956,7 +3955,7 @@ def is_num(s):
 
             return True
 
-        for sym in (self.syms.viewvalues if _IS_PY2 else self.syms.values)():
+        for sym in self.syms.values():
             # - sym.nodes empty means the symbol is undefined (has no
             #   definition locations)
             #
@@ -6896,12 +6895,11 @@ def _shell_fn(kconf, _, command):
         command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE
     ).communicate()
 
-    if not _IS_PY2:
-        try:
-            stdout = stdout.decode(kconf._encoding)
-            stderr = stderr.decode(kconf._encoding)
-        except UnicodeDecodeError as e:
-            _decoding_error(e, kconf.filename, kconf.linenr)
+    try:
+        stdout = stdout.decode(kconf._encoding)
+        stderr = stderr.decode(kconf._encoding)
+    except UnicodeDecodeError as e:
+        _decoding_error(e, kconf.filename, kconf.linenr)
 
     if stderr:
         kconf._warn("'{}' wrote to stderr: {}".format(
@@ -6938,9 +6936,6 @@ def _shell_fn(kconf, _, command):
 # Symbol will do. We test this with 'is'.
 _NO_CACHED_SELECTION = 0
 
-# Are we running on Python 2?
-_IS_PY2 = sys.version_info[0] < 3
-
 try:
     _UNAME_RELEASE = os.uname()[2]
 except AttributeError:
@@ -7233,11 +7228,11 @@ def _shell_fn(kconf, _, command):
 
 
 def _re_match(regex):
-    return re.compile(regex, 0 if _IS_PY2 else re.ASCII).match
+    return re.compile(regex, re.ASCII).match
 
 
 def _re_search(regex):
-    return re.compile(regex, 0 if _IS_PY2 else re.ASCII).search
+    return re.compile(regex, re.ASCII).search
 
 
 # Various regular expressions used during parsing

menuconfig.py

@@ -989,12 +989,7 @@ def _init():
     # Looking for this in addition to KEY_BACKSPACE (which is unreliable) makes
     # backspace work with TERM=vt100. That makes it likely to work in sane
     # environments.
-    _ERASE_CHAR = curses.erasechar()
-    if sys.version_info[0] >= 3:
-        # erasechar() returns a one-byte bytes object on Python 3. This sets
-        # _ERASE_CHAR to a blank string if it can't be decoded, which should be
-        # harmless.
-        _ERASE_CHAR = _ERASE_CHAR.decode("utf-8", "ignore")
+    _ERASE_CHAR = curses.erasechar().decode("utf-8", "ignore")
 
     _init_styles()
 

oldconfig.py

@@ -32,11 +32,6 @@
 from kconfiglib import Symbol, Choice, BOOL, TRISTATE, HEX, standard_kconfig
 
 
-# Python 2/3 compatibility hack
-if sys.version_info[0] < 3:
-    input = raw_input
-
-
 def _main():
     # Earlier symbols in Kconfig files might depend on later symbols and become
     # visible if their values change. This flag is set to True if the value of

testsuite.py

@@ -2699,16 +2699,12 @@ def verify_bad_argno(name):
 
     sys.path.pop(0)
 
-    # This test can fail on older Python 3.x versions, because they don't
-    # preserve dict insertion order during iteration. The output is still
-    # correct, just different.
-    if not (3, 0) <= sys.version_info <= (3, 5):
-        print("Testing KCONFIG_WARN_UNDEF")
+    print("Testing KCONFIG_WARN_UNDEF")
 
-        os.environ["KCONFIG_WARN_UNDEF"] = "y"
-        c = Kconfig("Kconfiglib/tests/Kundef", warn_to_stderr=False)
+    os.environ["KCONFIG_WARN_UNDEF"] = "y"
+    c = Kconfig("Kconfiglib/tests/Kundef", warn_to_stderr=False)
 
-        verify_equal("\n".join(c.warnings), """
+    verify_equal("\n".join(c.warnings), """
 warning: the int symbol INT (defined at Kconfiglib/tests/Kundef:8) has a non-int range [UNDEF_2 (undefined), 8 (undefined)]
 warning: undefined symbol UNDEF_1:
 
@@ -2747,7 +2743,7 @@ def verify_bad_argno(name):
 	visible if UNDEF_3
 """[1:-1])
 
-        os.environ.pop("KCONFIG_WARN_UNDEF")
+    os.environ.pop("KCONFIG_WARN_UNDEF")
 
 
     print("\nAll selftests passed\n" if all_passed else