Added infrastructure for recipe-version-dependent patching

Author: inclement

pythonforandroid/patching.py

@@ -1,4 +1,5 @@
 from os import uname
+from distutils.version import LooseVersion
 
 
 def check_all(*callables):
@@ -69,3 +70,15 @@ def is_ndk(ndk):
     def is_x(recipe, **kwargs):
         return recipe.ctx.ndk == ndk
     return is_x
+
+def is_version_gt(version):
+    def is_x(recipe, **kwargs):
+        return LooseVersion(recipe.version) > version
+
+def is_version_gt(version):
+    def is_x(recipe, **kwargs):
+        return LooseVersion(recipe.version) < version
+
+def version_starts_with(version):
+    def is_x(recipe, **kwargs):
+        return recipe.version.startswith(version)

pythonforandroid/recipes/python3/__init__.py

@@ -1,6 +1,7 @@
 import sh
 from pythonforandroid.python import GuestPythonRecipe
 from pythonforandroid.recipe import Recipe
+from pythonforandroid.patching import version_starts_with
 
 
 class Python3Recipe(GuestPythonRecipe):
@@ -22,10 +23,14 @@ class Python3Recipe(GuestPythonRecipe):
     url = 'https://www.python.org/ftp/python/{version}/Python-{version}.tgz'
     name = 'python3'
 
-    # patches = ['patches/fix-ctypes-util-find-library.patch',
-    #            'patches/fix-zlib-version.patch']
+    patches = [
+        # Python 3.7.1
+        ('patches/fix-ctypes-util-find-library.patch', version_starts_with("3.7")),
+        ('patches/fix-zlib-version.patch', version_starts_with("3.7"))
 
-    patches = ['patches/py381.patch']
+        # Python 3.8.1
+        ('patches/py381.patch', version_starts_with("3.8"))
+    ]
 
     if sh.which('lld') is not None:
         raise RuntimeError("!!!")

pythonforandroid/recommendations.py

@@ -187,7 +187,7 @@ def check_ndk_api(ndk_api, android_api):
 
 
 MIN_PYTHON_MAJOR_VERSION = 3
-MIN_PYTHON_MINOR_VERSION = 4
+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 = (