Made Python 2 check more robust

Author: inclement

pythonforandroid/bdistapk.py

@@ -75,7 +75,7 @@ def finalize_options(self):
     def run(self):
         self.prepare_build_dir()
 
-        from pythonforandroid.toolchain import main
+        from pythonforandroid.entrypoints import main
         sys.argv[1] = 'apk'
         main()
 

pythonforandroid/entrypoints.py

@@ -0,0 +1,19 @@
+from pythonforandroid.recommendations import check_python_version
+from pythonforandroid.util import BuildInterruptingException, handle_build_exception
+
+def main():
+    """
+    Main entrypoint for running python-for-android as a script.
+    """
+
+    try:
+        # Check the Python version before importing anything heavier than
+        # the util functions.  This lets us provide a nice message about
+        # incompatibility rather than having the interpreter crash if it
+        # reaches unsupported syntax from a newer Python version.
+        check_python_version()
+
+        from pythonforandroid.toolchain import ToolchainCL
+        ToolchainCL()
+    except BuildInterruptingException as exc:
+        handle_build_exception(exc)

pythonforandroid/logger.py

@@ -6,6 +6,8 @@
 from math import log10
 from collections import defaultdict
 from colorama import Style as Colo_Style, Fore as Colo_Fore
+
+# six import left for Python 2 compatibility during initial Python version check
 import six
 
 # This codecs change fixes a bug with log output, but crashes under python3

pythonforandroid/recommendations.py

@@ -1,7 +1,9 @@
 """Simple functions for checking dependency versions."""
 
+import sys
 from distutils.version import LooseVersion
 from os.path import join
+
 from pythonforandroid.logger import info, warning
 from pythonforandroid.util import BuildInterruptingException
 
@@ -93,7 +95,6 @@ def check_target_api(api, arch):
 RECOMMENDED_NDK_API = 21
 OLD_NDK_API_MESSAGE = ('NDK API less than {} is not supported'.format(MIN_NDK_API))
 
-
 def check_ndk_api(ndk_api, android_api):
     """Warn if the user's NDK is too high or low."""
     if ndk_api > android_api:
@@ -105,3 +106,28 @@ def check_ndk_api(ndk_api, android_api):
 
     if ndk_api < MIN_NDK_API:
         warning(OLD_NDK_API_MESSAGE)
+
+MIN_PYTHON_MAJOR_VERSION = 3
+MIN_PYTHON_MINOR_VERSION = 6
+MIN_PYTHON_VERSION = LooseVersion('{major}.{minor}'.format(major=MIN_PYTHON_MAJOR_VERSION,
+                                                           minor=MIN_PYTHON_MINOR_VERSION))
+PY2_ERROR_TEXT = (
+    'python-for-android no longer supports running under Python 2. Either upgrade to '
+    'Python {min_version} (recommended), or revert to python-for-android 2019.07.08. Note that '
+    'you *can* still target Python 2 on Android by including python2 in your requirements.').format(
+        min_version=MIN_PYTHON_VERSION)
+
+PY_MINOR_VERSION_ERROR_TEXT = (
+    'Your Python version {user_major}.{user_minor} is not supported by python-for-android, '
+    'please upgrade to {min_version} or higher.'
+    ).format(
+        user_major=sys.version_info.major,
+        user_minor=sys.version_info.minor,
+        min_version=MIN_PYTHON_VERSION)
+
+def check_python_version():
+    if sys.version_info.major < MIN_PYTHON_MAJOR_VERSION:
+        raise BuildInterruptingException(PY2_ERROR_TEXT)
+
+    if sys.version_info.minor < MIN_PYTHON_MINOR_VERSION:
+        raise BuildInterruptingException(PY_MINOR_VERSION_ERROR_TEXT)

pythonforandroid/toolchain.py

@@ -11,8 +11,9 @@
 from pythonforandroid import __version__
 from pythonforandroid.pythonpackage import get_dep_names_of_package
 from pythonforandroid.recommendations import (
-    RECOMMENDED_NDK_API, RECOMMENDED_TARGET_API)
+    RECOMMENDED_NDK_API, RECOMMENDED_TARGET_API, check_python_version)
 from pythonforandroid.util import BuildInterruptingException, handle_build_exception
+from pythonforandroid.entrypoints import main
 
 
 def check_python_dependencies():
@@ -100,14 +101,6 @@ def check_python_dependencies():
 toolchain_dir = dirname(__file__)
 sys.path.insert(0, join(toolchain_dir, "tools", "external"))
 
-def check_python_version():
-    py2_text = (
-        'python-for-android no longer supports running under Python 2. Either upgrade to '
-        'Python 3 (recommended), or revert to python-for-android 2019.07.08. Note that '
-        'you *can* still target Python 2 on Android by including python2 in your requirements.')
-    if sys.version_info.major < 3:
-        raise BuildInterruptingException(py2_text)
-
 def add_boolean_option(parser, names, no_names=None,
                        default=True, dest=None, description=None):
     group = parser.add_argument_group(description=description)
@@ -576,8 +569,6 @@ def add_parser(subparsers, *args, **kwargs):
         args, unknown = parser.parse_known_args(sys.argv[1:])
         args.unknown_args = unknown
 
-        check_python_version()
-
         if hasattr(args, "private") and args.private is not None:
             # Pass this value on to the internal bootstrap build.py:
             args.unknown_args += ["--private", args.private]
@@ -1188,12 +1179,5 @@ def build_status(self, _args):
                 print(recipe_str)
 
 
-def main():
-    try:
-        ToolchainCL()
-    except BuildInterruptingException as exc:
-        handle_build_exception(exc)
-
-
 if __name__ == "__main__":
     main()

pythonforandroid/util.py

@@ -6,15 +6,15 @@
 import sys
 from fnmatch import fnmatch
 from tempfile import mkdtemp
-try:
+
+# This Python version workaround left for compatibility during initial version check
+try:  # Python 3
     from urllib.request import FancyURLopener
-except ImportError:
+except ImportError:  # Python 2
     from urllib import FancyURLopener
 
 from pythonforandroid.logger import (logger, Err_Fore, error, info)
 
-IS_PY3 = sys.version_info[0] >= 3
-
 
 class WgetDownloader(FancyURLopener):
     version = ('Wget/1.17.1')

setup.py

@@ -94,15 +94,15 @@ def recursively_include(results, directory, patterns):
       install_requires=install_reqs,
       entry_points={
           'console_scripts': [
-              'python-for-android = pythonforandroid.toolchain:main',
-              'p4a = pythonforandroid.toolchain:main',
+              'python-for-android = pythonforandroid.entrypoints:main',
+              'p4a = pythonforandroid.entrypoints:main',
               ],
           'distutils.commands': [
               'apk = pythonforandroid.bdistapk:BdistAPK',
               ],
           },
       classifiers = [
-          'Development Status :: 4 - Beta',
+          'Development Status :: 5 - Production/Stable',
           'Intended Audience :: Developers',
           'License :: OSI Approved :: MIT License',
           'Operating System :: Microsoft :: Windows',
@@ -111,7 +111,6 @@ def recursively_include(results, directory, patterns):
           'Operating System :: MacOS :: MacOS X',
           'Operating System :: Android',
           'Programming Language :: C',
-          'Programming Language :: Python :: 2',
           'Programming Language :: Python :: 3',
           'Topic :: Software Development',
           'Topic :: Utilities',