I have installed Raspbian Lite OS in Raspberry Pi zero.
I found that Raspbian Lite comes with Python3 as default.
But I am gonna run some scripts that uses libraries that are Python2 Compatible.
So I tried to change the default Python version from Python3 to Python2 (Specifically Python2.7.18)
After so much searching and trying, instructions from [this page][1] made my job
Now if I try to check in command writing
python --version
It shows me that it is Python2.7.18
But the problem is I am not being able to install any packages using
sudo apt-get install <python-packagename>
It shows me Errors like
1.Package "python-pip" has no installation candidate (When I tried to install pip)
2. Package python-numpy has no installation candidate (when I tried to install numpy)
3. unable to locate package python-pyaudio (when I tried to install pyaudio)
I am searching but no solution.
Can anyone please help? I am frozen in a critical stage of my project .
Generally, for new raspbian/raspios os with python 3 by default, it is not suggested to replace the system python interpreter to python 2, it may break some system component's dependency.
Instead, you can create a python 2 virtual env, if you need to run python2 scripts.
sudo apt-get install python3-pip
pip install virtualenv
virtualenv -p /usr/bin/python2.7 venv
source venv/bin/activate
You can test the python version as following,
(venv) $ python --version
enter image description here I am trying to installing Rasa. I run this command rasa init. It's working fine. But when I am trying to run this command rasa x it throws an error as shown in the above image(link). One solution I have found is to remove domain_path=domain_path from the x.py file which can be found in such a path: C:\Users\Admin\anaconda3\envs\Myenv\Lib\site-packages\rasa\cli\x.py . Even though the other solution I've heard is to downgrade the version of Python and pip. Versions are (Rasa Version: 2.8.1, Python Version:3.7, pip version: 20.2) But still, I can't get rid of it. If anybody has a solution, please help.
To solve this issue, please follow the below steps:
pip install rasa==2.8.1
check rasa --version
then install
pip install rasa-sdk==2.8.1
Install this version rasa-x==0.39.3
pip install rasa-x==0.39.3 --extra-index-url https://pypi.rasa.com/simple
Some know errors:
ImportError: cannot import name ‘RowProxy’ from ‘sqlalchemy.engine’ try running pip install SQLAlchemy==1.3.22 should fix it.)
And, if you get an error not being able to import yaml then run pip install pyyaml.
~ $ gdalinfo --version
gdalinfo: symbol lookup error: /lib/libgdal.so.28: undefined symbol: proj_crs_get_datum_ensemble
Recently upgraded to Ubuntu 21.04 and things stopped working, tried removing all gdal, qgis installation and reinstall again and this is the latest. Previous error was https://gist.github.com/adoug/f551c96ae49bcf0dd4905cfb3ed1c910. Installing qgis from gui also comes up with an error Unable to install QGIS Desktop: Error while installing package: installed qgis-providers package post-installation script subprocess returned error exit status 127
~ $ pip3 install gdal
Requirement already satisfied: gdal in /usr/lib/python3/dist-packages (3.2.2)
~ $ pip3 uninstall gdal
Found existing installation: GDAL 3.2.2
Not uninstalling gdal at /usr/lib/python3/dist-packages, outside environment /usr
Can't uninstall 'GDAL'. No files were found to uninstall.
The whole install seems to be broken, is there a way to clean all and resinstall or somehow recover from this?
Not really for a fix for current issue, but used fresh anaconda install as a workaround to get gdal working again
conda update --all
conda install -c conda-forge gdal
How do I install PIL?
>pip install PIL
Downloading/unpacking PIL
Could not find any downloads that satisfy the requirement PIL
Some externally hosted files were ignored (use --allow-external PIL to allow).
Cleaning up...
No distributions at all found for PIL
Storing debug log for failure in /root/.pip/pip.log
>pip uninstall PIL
Can't uninstall 'PIL'. No files were found to uninstall.
pip install PIL --allow-external PIL --allow-unverified PIL
This is due to changes in the new version of Pip. Run pip --version and I'm willing to bet you are running 1.5. See the changelog here. This new default behavior enhances security. In PIL's case, the file you are installing actually comes from effbot.org (thus --allow-external) and PyPi doesn't have a checksum to guarantee validity (thus --allow-unverified).
Also, you might consider using the Pillow replacement to PIL.
Updated info for those reading in 2016:
--allow-external
and
--allow-unverified
were recently deprecated. Installing packages external to PyPi using pip is no longer supported: http://www.python.org/dev/peps/pep-0470/
As an alternative, when you really need to install that external package, you can download the source code and run its setup.py. For example, for PIL 1.1.7, download from http://www.pythonware.com/products/pil/, then:
$ tar xvfz Imaging-1.1.7.tar.gz
$ cd Imaging-1.1.7
$ python setup.py install
(^ from the PIL README)
If you only want to install the package to a specific virtualenv, you can just activate your virtualenv first. ** thanks #Caumons
Alternatively, substitute the path to your virtualenv for 'python' in the third line, e.g.:
$ /home/username/virtualenv-name/bin/python setup.py install
Is it possible to install psycopg2 into a virtualenv when PostgreSQL isn't installed on my development system—MacBook Pro with OS X 10.6?
When I run pip install psycopg2 from within my virtualenv, I received the error shown below.
I'm trying to connect to a legacy database on a server using Django, and I'd prefer not to install PostgreSQL on my development system if possible.
Why not install PostgreSQL?
I received an error when installing PostgreSQL using homebrew. I have Xcode4—and only Xcode4—installed on my MacBook Pro and am thinking it's related to missing gcc 4.0. However, this is a problem for another StackOverflow question.
Update 8:37 AM on April 12, 2011: I'd still like to know if this is possible without installing PostgreSQL on my MacBook Pro. However, I ran brew update and forced a reinstallation of ossp-uuid with brew install --force ossp-uuid and now brew install postgresql works. With PostgreSQL successfully installed, I was able to pip install psycopg2 from within my virtualenv.
Error from pip install psycopg2
$ pip install psycopg2
Downloading/unpacking psycopg2
Running setup.py egg_info for package psycopg2
Error: pg_config executable not found.
Please add the directory containing pg_config to the PATH
or specify the full executable path with the option:
python setup.py build_ext --pg-config /path/to/pg_config build ...
or with the pg_config option in 'setup.cfg'.
Complete output from command python setup.py egg_info:
running egg_info
writing pip-egg-info/psycopg2.egg-info/PKG-INFO
writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
warning: manifest_maker: standard file '-c' not found
Error: pg_config executable not found.
Please add the directory containing pg_config to the PATH
or specify the full executable path with the option:
python setup.py build_ext --pg-config /path/to/pg_config build ...
or with the pg_config option in 'setup.cfg'.
----------------------------------------
Command python setup.py egg_info failed with error code 1
Storing complete log in /Users/matthew/.pip/pip.log
Preliminary Research
Below are the articles I read as preliminary research:
Installing psycopg2 to use Django with PostgreSQL on OS X
Installing psycopg2 on OS X
Using psycopg2 with virtualenv on Ubuntu JauntyLucid
Postgres, psycopg2, virtualenv install hints
apt-get install libpq-dev
helped me on debian squeeze
From comments:
apt-get install python-dev-is-python3
psycopg depends on pg_config command, and if you don't have it, you can't install psycopg.
If system installation is a problem to you, why don't you try compiling PostgreSQL and including generated bin files in your $PATH? Like:
export PATH=/path/to/compiled/postgresql/bin:"$PATH"
pip install psycopg2
brew install postgresql
export LDFLAGS="-L/usr/local/opt/openssl/lib"
export CPPFLAGS="-I/usr/local/opt/openssl/include"
pip3 install psycopg2
apt-get install libpq-dev
helped me in debian squeeze too . After that do pip install psycopg2. I faced problem of pg_config not found problem when i was setting up my environment on heroku , now its working fine .
You need to install the python-dev package in order to make use of python extensions such as psycopg2. I don't know how to install packages in mac but I run the following commands to install a python package on my Ubuntu machine.
sudo apt-get install python-dev
Or
sudo apt-get install python3-dev
if you are using Python3.x.
Once the installation is finished run the following command within your virtual environment.
pip install psycopg2
You don't need the complete PostgreSQL installed: you only need the client side libraries.
I solved it in MAC OSX using :
$ wget https://ftp.postgresql.org/pub/source/v9.5.3/postgresql-9.5.3.tar.bz2
$ tar xfv postgresql-9.5.3.tar.bz2
$ cd postgresql-9.5.3
$ ./configure
$ make
$ cd src/bin/pg_config
$ export PATH=`pwd`:"$PATH"
$ pip install psycopg2
Use pip install psycopg2-binary, it worked for me when pip install psycopg2 wasn't working.
Using the method you described in your April 12th update, I was able to install PostgreSQL(+1). Note that I originally was running Python 2.7.1 (32bit) and homebrew threw several errors and warnings regarding using a 32bit version of Python. I have since switched the 64/32 bit version of 2.7.1 and it works like a champ.
Regarding the pyscopg2, I was able to install it into my virtual environment from source by editing setup.cfg. I set pg_config to correct path inside homebrew's Cellar (pg_config=/usr/local/Cellar/postgresql/9.0.4/bin/pg_config). After saving the changes, I ran python setup.py install with zero issues. It's worth noting that I did not set the Mac's default python setting to 32 bit. I used the new 64 bit from start to finish.
After looking over some of the documentation, I think if I added homebrew's postgresql path to the system path I could have used pip to install it.
Reference:
http://favosdream.blogspot.com/2009/09/make-psycopg2-and-readline-work-in-snow.html
Update 6-8-2011:
While porting a project written on OS X to Windows 7, I found out that I had to install PostgreSQL on Windows as well. This ended up creating another user on my start up screen and other things that I just didn't like. While doing some digging I found Windows drivers for PostgreSQL here. I have since uninstalled the full PostgreSQL and installed the ODBC drivers which, thus far, work great.
To address the original question, after doing a bit more digging I think I found the equivalent ODBC for OS X here. I have not had a chance to try them out, but the concept works very well on Windows 7. I will update this when I get a chance to try them out. Until then, I hope this helps.
All from the above doesn't work for me (OS Catalina 10.15.1)
There was a conflict with classical postgres and homebrew version.
Please delete homebrew version by command
$ brew uninstall postgresql
and then install it from the official website:
$ sudo mkdir -p /etc/paths.d && echo /Applications/Postgres.app/Contents/Versions/latest/bin | sudo tee /etc/paths.d/postgresapp
It is actual for a simple psycopg2 install or django-heroku package.
if you have recently updated python or changed default python (let's say from 3.6 to 3.8). The following code
sudo apt-get install python-dev OR sudo apt-get install python3-dev
will be installing/working for the previous python version.
so if you want this command to work for the recently updated/changed python version try mentioning that specific version like python3.8 in command like
sudo apt-get install python3.8-dev
try above with following
pip install wheel
export PATH=/path/to/compiled/postgresql/bin:"$PATH"
sudo apt-get install libpq-dev
sudo apt-get install python3.x-dev **Change x with your version, eg python3.8**
pip install psycopg2-binary
pip install psycopg2
As I never needed to install postgresql database on this server I installed the following libraries on Ubuntu 14_04 version before running pip install psycopg2 on the same server
apt-get install libpq-dev python-dev
and then executed pip install psycopg2 within virtual env.
Output
Collecting psycopg2
Using cached psycopg2-2.6.1.tar.gz
Building wheels for collected packages: psycopg2
Running setup.py bdist_wheel for psycopg2
Stored in directory: /root/.cache/pip/wheels/e2/9a/5e/7b620848bbc7cfb9084aafea077be11618c2b5067bd532f329
Successfully built psycopg2
Installing collected packages: psycopg2
Successfully installed psycopg2-2.6.1
I know you are asking for development environment but if you are deploying on server say, Heroku.
Just add below line in the requirements.txt of your project.
django-heroku==0.3.1
As this package itself will install the required packages like psycopg2 on server deployment.
Try to specify the version and it'll works, do it inside the venv
pip install psycopg2-binary==2.8.6
based on my experience, apt install libpq-dev then try to install psycopg2 inside venv will fix many issues, however for more information you can refer to this link:
https://www.psycopg.org/docs/install.html