Develop Reference

Convert .py to .apk problem with buildozer

I'm a beginner into python language. I want to develop an android app. I've wrote some code and few days ago I wanted to see how my app looks on mobile before continue.
I've tried all methods to convert .py to .apk but failed. I've tried with google colab, I've installed a VM... but nothing worked. If I use google colab, after all I receive an .apk, but when I install it on my phone, doesn't work... The app opens, but closes imediatly.
If I use VM I receive this error: error message
This is a picture of all my components: components
For google colab I'm using this commands :
!pip install buildozer
!pip install cython==0.29.19
!sudo apt-get install -y
python3-pip
build-essential
git
python3
python3-dev
ffmpeg
libsdl2-dev
libsdl2-image-dev
libsdl2-mixer-dev
libsdl2-ttf-dev
libportmidi-dev
libswscale-dev
libavformat-dev
libavcodec-dev
zlib1g-dev
!sudo apt-get install -y
libgstreamer1.0
gstreamer1.0-plugins-base
gstreamer1.0-plugins-good
!sudo apt-get install build-essential libsqlite3-dev sqlite3 bzip2 libbz2-dev zlib1g-dev libssl-dev openssl libgdbm-dev libgdbm-compat-dev liblzma-dev libreadline-dev libncursesw5-dev libffi-dev uuid-dev libffi6
!sudo apt-get install libffi-dev
!buildozer init
!buildozer -v android debug
!buildozer android clean
This is a picture with my google colab: google colab & buildozer.spec
I've tried all tutorials I've found on internet but nothing worked.
The code works perfectly on PC!
Please, help me!

You could try pydroid 3... This isn't really a solution but for now, if you are trying to see how your app looks on an Android device. Get Pydroid 3 from play store. Create a new file and copy your code across into the app and run it... It will run kivy but not kivymd....
If your getting the apk from colab it might be a problem in the code, trying it on pyroid my highlight something and if so when that's altered the new APK might work

Can you connect phone to your system and run this command
adb logcat -s python and then open the app in mobile. This will give you a log why your app crashed. I suspect some issue with the requirements in buildozer.
Could you run the command and share the log?

I think you should see this solution
You can use this video to test that solution (It's in Spanish but I hope you can translate it)
I tried and it works
The key is to edit buildozer.spec
After that you can test your own solution

CoreOS build docker image (CP100A Training)

I'm currently working on the "Google cloud platform fundamentals" labs and I'm running into issues.
Each time I have to use a CoreOS instance to spin up a docker instance there is an error I get.
For example: in the Cloud SQL lab, at some point I have to build a docker image of the folder I just cloned from a git repo using the command:
docker build -t cp100/cloudsql-python cp100-cloud-sql-python
which gives me a wall of text that ends with an error :
Downloading/unpacking flask
Cannot fetch index base URL http://pypi.python.org/simple/
Could not find any downloads that satisfy the requirement flask
No distributions at all found for flask
Storing complete log in /root/.pip/pip.log`
The thing Is, there is no "/root/.pip/pip.log" file.
So here are my questions :
Are the tutorials outdated, and if yes, where can I find the up-to-date tutorials?
Why does it happen? I think It is because pip or Python or both are not installed but shouldn't the command docker build take the installation in charge?
How can I fix it?
the cp100-cloud-sql-python file is available at https://github.com/GoogleCloudPlatformTraining/cp100-cloud-sql-python.git
Thanks for your answers.

Ok I found the answers by myself:
So the reason it doesn't work is that pip (and easy install) use HTTP and pypi.python.org requires HTTPS, the issue is further documented here :
https://bugzilla.redhat.com/show_bug.cgi?id=1510444
So in order to fix it I modified the Dockerfile inside the app from
FROM google/debian:wheezy
MAINTAINER Sharif Salah <sharif.salah+docker#gmail.com>
RUN apt-get update && \
apt-get install -y python-dev python-pip python-mysqldb && \
pip install flask
ADD app /app
EXPOSE 80
CMD [ "python", "/app/app.py" ]
to
FROM google/debian:wheezy
MAINTAINER Sharif Salah <sharif.salah+docker#gmail.com>
RUN apt-get update && \
apt-get install -y python-dev python-setuptools python-mysqldb && \
easy_install -i https://pypi.python.org/simple flask
ADD app /app
EXPOSE 80
CMD [ "python", "/app/app.py" ]
which will force easy_install to use the address specified after the -i.
It worked in my case but as documented on Bugzilla, it may not work for everything.
I hope this will help someone

"ssl module in Python is not available"

still advancing in my tutorial to learn python, I was told to do
sudo -H pip install requests
I get the following :
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting requests
Could not fetch URL https://pypi.python.org/simple/requests/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping
Could not find a version that satisfies the requirement requests (from versions: )
No matching distribution found for requests
would someone know what I need to do to fix that once for all ?
thanks so much in advance

I use Linux distros and face the problem since the new installation of Python 3.6.
I tried a couple of solution and finally solved the problem. The steps I followed are as below.
On Debian like distros
sudo apt-get install build-essential checkinstall libreadline-gplv2-dev ibncursesw5-dev libssl-dev libsqlite3-dev tk-dev libgdbm-dev libc6-dev libbz2-dev
Change the directory to the Python3.6 location
cd /path/to/Python3.6/Module/
In the module directory, open the Setup file with your preferred text editor
vi Setup
Search for SSL and uncomment the related lines.
ssl _ssl.c \
-DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \
-L$(SSL)/lib -lssl -lcrypto
Save the file and on the root folder of your Python package, run the following command.
make
sudo make install
And finally, run the pip3 to install your required module(s).

Running ./configure with --enable-optimizations did the trick.
Here are the steps that worked for me on a Ubuntu 16.04 LTS box-
The lines related to ssl in the Modules/Setup* files are commented
cd to the directory where you have the Python tar extracted
cd /../../../Python-3.7.4/
Run configure with optimizations enabled
./configure --enable-optimizations
Run make and then make install
make
make install

I encountered this problem running pip on Powershell on Windows, using the Anaconda distribution. I was running it inside VSCode, but I don't think it makes much difference.
A quick turnaround for me was installing what I needed using the Anaconda prompt, which works fine.

I encountered the problem when installing 3.8.11. I tried the above posts but they didn't work.
This is how I finally made it compile:
1) Install openssl 1.1.1g;
2) untar the tarball;
3) enter the source directory;
4) run ./config --prefix=/usr/local/openssl_1.1 --openssldir=/usr/local/openssl_1.1
to install to /usr/local/openssl_1.1.
make & make install.
You can customize the directory.
5)Download python 3.8 source tarball;
6)untar the tarball. Enter the source/Modules;
7) edit the file Setup;
8) find the lines:
SSL=/usr/local/ssl
ssl _ssl.c \
-DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \
-L$(SSL)/lib -lssl -lcrypto
change SSL=/usr/local/ssl to SSL=/usr/local/openssl_1.1
9) Switch to the source directory. run
./configure --prefix=/usr/local/python3.8 --with-openssl=/usr/local/openssl_1.1
10) export LD_LIBRARY_PATH=/usr/local/openssl_1.1/lib:$LD_LIBRARY_PATH
11) make & make install. If you need sudo, also export LD_LIBRARY_PATH in sudo

This command worked very well for me.
cd Python-3.6.2
./configure --with-ssl
make
sudo make install

I encountered the same problem in Windows 10.
What I did was:
Step 1: go to https://pypi.python.org/simple/requests and download the latest version (e.g., requests-2.21.0.tar.gz).
Step 2: unzip the downloaded file into a folder (e.g., c:\temp\requests-2.21.0). You can use 7zip for that purpose.
Step 3: pip install c:\temp\requests-2.21.0
Note: pip can also install a local folder.
It worked for me.

Segmentation fault (core dumped) Error in PyQt5

I just installed PyQt 5.7.0 on my google compute engine machine which running on a ubuntu 16.04:
However, when I wanted to run PyQt and import some module, it produce Segmentation fault (core dumped) error as shown:
Can I know how do I solve it? I have been searching an answer for this for hours and still can't find an answer. Will be greatly appreciated if anyone could help.

You can try (as explained in the comments) to compile PyQt5.7 yourself, using a different version of Python (3.4.3 and 3.4.4 worked for me, everything above 3.5 did not). Note that I also compiled Qt5.7 myself, but you can use the one provided by the installer. Here is a short, hopefully exhaustive, set of commands to setup a virtual environment:
Install dependencies using apt:
sudo apt-get install -y build-essential libgl1-mesa-dev libx11-dev libxext-dev libxfixes-dev libxi-dev libxrender-dev libxcb1-dev libx11-xcb-dev libxcb-glx0-dev libfontconfig1-dev libfreetype6-dev libglu1-mesa-dev libssl-dev libcups2-dev python3-pip git
Install Python 3.4.4:
cd ~/Downloads
wget https://www.python.org/ftp/python/3.4.4/Python-3.4.4.tar.xz
tar xf Python-3.4.4.tar.xz
cd Python-3.4.4
./configure
sudo make altinstall
Create the virtual environment:
sudo pip3 install virtualenv
virtualenv -p /usr/local/bin/python3.4 ~/python34
source ~/python34/bin/activate
Install Qt:
cd ~/Downloads
git clone git://code.qt.io/qt/qt5.git
cd ~/Downloads/qt5
git checkout 5.7
./init-repository
./configure -prefix ~/Qt/5.7/gcc_64 -opensource -nomake examples -nomake tests -release -confirm-license
make -j 5
make install
Install SIP:
cd ~/Downloads
wget http://downloads.sourceforge.net/project/pyqt/sip/sip-4.18.1/sip-4.18.1.tar.gz
tar xf sip-4.18.1.tar.gz
cd sip-4.18.1
python configure.py
make
sudo make install
Install PyQt:
cd ~/Downloads
wget http://downloads.sourceforge.net/project/pyqt/PyQt5/PyQt-5.7/PyQt5_gpl-5.7.tar.gz
tar xf PyQt5_gpl-5.7.tar.gz
cd PyQt5_gpl-5.7
python configure.py --qmake ~/Qt/5.7/gcc_64/bin/qmake --disable QtPositioning --no-qsci-api --no-designer-plugin --no-qml-plugin --confirm-license
make -j 5
sudo make install

Caveats:
I'm going to assume that you can't run any GUI programs right now in your vm.
I'm not that familiar with GCE platform and have not tried what I'm going to propose
Follow the steps at Your desktop on Google Cloud Platform to install a desktop GUI manager in the GCE vm (it will be X11-based for Linux OS), as well as vnc server.
Once you are vnc'd in to your vm using realvnc or tightvnc viewer, a GUI app will likely run. You may have to change the X11 DISPLAY variable -- eventhough the above link does not discuss this -- because AFAIR *nix systems use a separate desktop session for VNC than the one currently logged in.
I doubt it will run if there is no user logged on to the GCE vm.

If you installed PyQt5 with apt or apt-get, now do also
sudo pip3 install pyqt5

You cannot run a GUI program (PyQt) remotely, unless both machines use X11 protocol with properly set DISPLAY variables and xhost permissions. I doubt that Google compute engine is configurable to run in the X11 mode.

When you import PyQt5, it will also import PyQt5.QtCore because PyQt5.QtCore is part of PyQt5.

Install cx_Oracle for Python

Am on Debian 5, I've been trying to install cx_oracle module for python without any success. First, I installed oracle-xe-client and its dependency (followed tutorial in the following link here).
Then, I used the scripts in /usr/lib/oracle/xe/app/oracle/product/10.2.0/client/bin to populate environment variables such as PATH, ORACLE_HOME and NLS_LANG.
Once, this was completed, I tried to run:
sudo easy_install cx_oracle
But I keep getting the following error:
Searching for cx-oracle
Reading http://pypi.python.org/simple/cx_oracle/
Reading http://cx-oracle.sourceforge.net
Reading http://starship.python.net/crew/atuining
Best match: cx-Oracle 5.0.4
Downloading http://prdownloads.sourceforge.net/cx-oracle/cx_Oracle-5.0.4.tar.gz?download
Processing cx_Oracle-5.0.4.tar.gz
Running cx_Oracle-5.0.4/setup.py -q bdist_egg --dist-dir /tmp/easy_install-xsylvG/cx_Oracle-5.0.4/egg-dist-tmp-8KoqIx
error: cannot locate an Oracle software installation
Any idea what I missed here?

The alternate way, that doesn't require RPMs. You need to be root.
Dependencies
Install the following packages:
apt-get install python-dev build-essential libaio1
Download Instant Client for Linux x86-64
Download the following files from Oracle's download site:
Extract the zip files
Unzip the downloaded zip files to some directory, I'm using:
/opt/ora/
Add environment variables
Create a file in /etc/profile.d/oracle.sh that includes
export ORACLE_HOME=/opt/ora/instantclient_11_2
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME
Create a file in /etc/ld.so.conf.d/oracle.conf that includes
/opt/ora/instantclient_11_2
Execute the following command
sudo ldconfig
Note: you may need to reboot to apply settings
Create a symlink
cd $ORACLE_HOME
ln -s libclntsh.so.11.1 libclntsh.so
Install cx_Oracle python package
You may install using pip
pip install cx_Oracle
Or install manually
Download the cx_Oracle source zip that corresponds with your Python and Oracle version. Then expand the archive, and run from the extracted directory:
python setup.py build
python setup.py install

I recommend that you grab the rpm files and install them with alien. That way, you can later on run apt-get purge no-longer-needed.
In my case, the only env variable I needed is LD_LIBRARY_PATH, so I did:
echo export LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client/lib >> ~/.bashrc
source ~/.bashrc
I suppose in your case that path variable will be /usr/lib/oracle/xe/app/oracle/product/10.2.0/client/lib.

The following worked for me, both on mac and Linux. This one command should download needed additional files, without need need to set environment variables.
python -m pip install cx_Oracle --pre
Note, the --pre option is for development and pre-release of the Oracle driver. As of this posting, it was grabbing cx_Oracle-6.0rc1.tar.gz, which was needed. (I'm using python 3.6)

Thx Burhan Khalid, I overlooked your "You need to be root" quote, but found the way when you are not the root here.
At point 7 you need to use:
sudo env ORACLE_HOME=$ORACLE_HOME python setup.py install
Or
sudo env ORACLE_HOME=/path/to/instantclient python setup.py install

Thanks Burhan Khalid. Your advice to make a a soft link make my installation finally work.
To recap:
You need both the basic version and the SDK version of instant client
You need to set both LD_LIBRARY_PATH and ORACLE_HOME
You need to create a soft link (ln -s libclntsh.so.12.1 libclntsh.so in my case)
None of this is documented anywhere, which is quite unbelievable and quite frustrating. I spent over 3 hours yesterday with failed builds because I didn't know to create a soft link.

I think it may be the sudo has no access to get ORACLE_HOME.You can do like this.
sudo visudo
modify the text add
Defaults env_keep += "ORACLE_HOME"
then
sudo python setup.py build install

Alternatively you can install the cx_Oracle module without the PIP using the following steps
Download the source from here https://pypi.python.org/pypi/cx_Oracle
[cx_Oracle-6.1.tar.gz ]
Extract the tar using the following commands (Linux)
gunzip cx_Oracle-6.1.tar.gz
tar -xf cx_Oracle-6.1.tar
cd cx_Oracle-6.1
Build the module
python setup.py build
Install the module
python setup.py install

This just worked for me on Ubuntu 16:
Download ('instantclient-basic-linux.x64-12.2.0.1.0.zip' and 'instantclient-sdk-linux.x64-12.2.0.1.0.zip') from Oracle web site and then do following script (you can do piece by piece and I did as a ROOT):
apt-get install -y python-dev build-essential libaio1
mkdir -p /opt/ora/
cd /opt/ora/
## Now put 2 ZIP files:
# ('instantclient-basic-linux.x64-12.2.0.1.0.zip' and 'instantclient-sdk-linux.x64-12.2.0.1.0.zip')
# into /opt/ora/ and unzip them -> both will be unzipped into 1 directory: /opt/ora/instantclient_12_2
rm -rf /etc/profile.d/oracle.sh
echo "export ORACLE_HOME=/opt/ora/instantclient_12_2" >> /etc/profile.d/oracle.sh
echo "export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$ORACLE_HOME" >> /etc/profile.d/oracle.sh
chmod 777 /etc/profile.d/oracle.sh
source /etc/profile.d/oracle.sh
env | grep -i ora # This will check current ENVIRONMENT settings for Oracle
rm -rf /etc/ld.so.conf.d/oracle.conf
echo "/opt/ora/instantclient_12_2" >> /etc/ld.so.conf.d/oracle.conf
ldconfig
cd $ORACLE_HOME
ls -lrth libclntsh* # This will show which version of 'libclntsh' you have... --> needed for following line:
ln -s libclntsh.so.12.1 libclntsh.so
pip install cx_Oracle # Maybe not needed but I did it anyway (only pip install cx_Oracle without above steps did not work for me...)
Your python scripts are now ready to use 'cx_Oracle'... Enjoy!

This worked for me
python -m pip install cx_Oracle --upgrade
For details refer to the oracle quick start guide
https://cx-oracle.readthedocs.io/en/latest/installation.html#quick-start-cx-oracle-installation

If you are trying to install in MAC , just unzip the Oracle client which you downloaded and place it into the folder where you written python scripts.
it will start working.
There is too much problem of setting up environmental variables.
It worked for me.
Hope this helps.
Thanks

Try to reinstall it with the following code:
!pip install --proxy http://username:windowspwd#10.200.72.2:8080 --upgrade --force-reinstall cx_Oracle

If you require to install a specific version of cx_Oracle, like 7.3 which was the last version with support for Python 2, you can do the following:
python -m pip install cx_Oracle==7.3