TypeError: must be str, not bytes

Versions

• Python: 3.5.3 (running in virtualenv and in root) (seems to be running Python 3.7.1 on Android based on the logs)
• OS: Ubuntu 17:04
• Kivy: 1.9.1
• Cython: 0.28.6
• Andoid 7.0 (on Samsung Galaxy S6)

Description

I have compiled a very basic helloWorld app as below. The app works fine on Ubuntu and also compiles fine into apk using buildozer.

__version__ = '1.0'
from kivy.app import App
from kivy.uix.button import Button
 
class Hello(App):
    def build(self):
        btn = Button(text='Hello World')
        return  btn
 
Hello().run()

When I run on Android the app immediately closes before displaying the hello world screen. After working through logs produced with adb logcat I see the following…

06-25 19:48:52.272  2100  2118 I python  :  Traceback (most recent call last):
06-25 19:48:52.272  2100  2118 I python  :    File "/home/lee/KivyProjects/helloWorld/.buildozer/android/app/main.py", line 3, in <module>
06-25 19:48:52.273  2100  2118 I python  :    File "/home/lee/KivyProjects/helloWorld/.buildozer/android/platform/build/build/python-installs/helloWorld/kivy/app.py", line 319, in <module>
06-25 19:48:52.273  2100  2118 I python  :    File "/home/lee/KivyProjects/helloWorld/.buildozer/android/platform/build/build/python-installs/helloWorld/kivy/base.py", line 26, in <module>
06-25 19:48:52.274  2100  2118 I python  :    File "/home/lee/KivyProjects/helloWorld/.buildozer/android/platform/build/build/python-installs/helloWorld/kivy/clock.py", line 410, in <module>
06-25 19:48:52.274  2100  2118 I python  :    File "<frozen importlib._bootstrap>", line 983, in _find_and_load
06-25 19:48:52.274  2100  2118 I python  :    File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
06-25 19:48:52.275  2100  2118 I python  :    File "<frozen importlib._bootstrap>", line 668, in _load_unlocked
06-25 19:48:52.275  2100  2118 I python  :    File "<frozen importlib._bootstrap>", line 638, in _load_backward_compatible
06-25 19:48:52.276  2100  2118 I python  :    File "/home/lee/KivyProjects/helloWorld/.buildozer/android/platform/build/build/other_builds/python3-libffi-openssl-sqlite3/armeabi-v7a__ndk_target_21/python3/Lib/ctypes/util.py", line 73, in <module>
06-25 19:48:52.276  2100  2118 I python  :    File "/home/lee/KivyProjects/helloWorld/.buildozer/android/platform/build/build/python-installs/helloWorld/android/__init__.py", line 8, in <module>
06-25 19:48:52.277  2100  2118 I python  :    File "android/_android.pyx", line 162, in init android._android
06-25 19:48:52.277  2100  2118 I python  :  TypeError: must be str, not bytes
06-25 19:48:52.277  2100  2118 I python  : Python for android ended.

This appears to be the same issue raised as 1691 under the title “unicode error during startup (python3, numpy, opencv) - patch included #1691”. If I am reading this patch correctly the current file _android.pyx should have the following changes

removed this line python_act = autoclass(JAVA_NAMESPACE + u’.PythonActivity’)

added these lines java_namespace = JAVA_NAMESPACE.decode() if isinstance(JAVA_NAMESPACE, bytes) else JAVA_NAMESPACE python_act = autoclass(java_namespace + u’.PythonActivity’)

Yet when I look at the current code on Github for _android.pyx I do not see these changes applied. Has this fix somehow been removed from the current version? How can i apply this fix to my system?

[ghost]

I just looked at the code in pythonforandroid/build.py and it seems to me this is a bug, it uses “Cython” as a binary rather than using sys.executable/python2/python3 -m cython which should probably fix this. I’ll see if I can change that, it seems fixable to me

[ghost]

@synccodes did you try sudo pip uninstall cython, pip uninstall cython (to make sure it’s gone from all places) and then sudo pip3 install cython? If it’s really cython being installed via python 2 that should possibly fix it