Develop Reference

Error "Invalid version: '0.23ubuntu1' (package: distro-info)"

Originally, my app crashed with error ERROR: Failed building wheel for pycairo (in the picture)
Failed to build pycairo
I tried to fix it by running several commands
sudo apt install libcairo2-dev
sudo apt install cloud-init
Gave the same error. No fix.
then I tried uninstalling the requirements.txt and reinstalled
pip uninstall -r requirements.txt
pip install -r requirements.txt
Did not solve the issue.
then I tried the below command, but I still got the same error "Failed building wheel for pycairo":
pip3 install --upgrade pip (from this thread: ERROR: Could not build wheels for scipy which use PEP 517 and cannot be installed directly
then I tried this command:
pip install --upgrade pip setuptools wheel
and I got this error in the picture: "Invalid version: '0.23ubuntu1'"
Invalid version: '0.23ubuntu1'
I tried to also delete this package but it's showing that package not found:
command I used: sudo apt-get remove distro-info
Error:
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'distro-info' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 283 not upgraded.
I searched for solutions but did not find any regarding the error "Invalid version: '0.23ubuntu1'". Now, when I run "flask run", I get error: -bash: /home/ktai/.local/bin/flask: No such file or directory
Would appreciate any help!
I tried several command lines but nothing worked

I learned from this answer that there is a "bug" with versions of setuptools causing this specific Invalid version: '0.23ubuntu1' error.
Despite seeing errors with all sorts of pip commands including pip install, I was surprised to see that this downgrade command (from the answer linked) appears to resolve the issue:
pip install --upgrade --user setuptools==58.3.0

Are you using ubuntu 20.04 by chance?
I had a similar issue but it had to do nothing with pycairo so the situation might be different for you.
The existence of distro-info (with a version not compliant to PEP-440) among my Python packages was leading to the error message from your post's title whenever i tried to install another package.
For me, this one helped: (so you were close with the apt-get remove...)
python3 -m pip uninstall -y distro-info
In my case, it seems like it didnt break anything important so i will keep it like this.
But there is no guarantee the same works for you as well. Also, you might get it back the next time you install packages from your requirements.txt file.
If I understood this thread correctly, there might be updates with a compliant version of this package depending on which Ubuntu version you are using.

This error arises from PEP 440 (Python Enhancement Proposal #440), which enforces conventions for naming of Python packages, and this error seems to really only happen on Debian-based distros like Ubuntu. For example, I have been trying to install a package via pip and get an error:
pkg_resources.extern.packaging.version.InvalidVersion: Invalid version: '1.1build1' (package: distro-info)
So it's telling us that 1.1build1 is an invalid version name per PEP 440, and it's probably getting the distro-info package from, in my case, Ubuntu (came preinstalled).
I can get around this by using a Python virtual environment and not allowing it to use system-site-packages, sometimes called "global packages".
The solution is to remove the offending package and reinstall a version of it that meets PEP 440 requirements (e.g. following the "0.0.0" convention. "1.2.0" for example is fine, "1.2build3" is not).
pip uninstall -y distro-info
pip install distro-info==1.0
Additionally, within PyCharm, I can navigate to the Python Interpreter settings, choose the interpreter I am using from the Python Interpreter dropdown, and confirm that the version of distro-info it's trying to use is 1.1build1. To "upgrade" this to 1.0, I can double-click on the "1.0" under the "Latest Version" column and select "Install Package" from the modal that pops up.
If this or the above command to remove distro-info isn't working, you can use this same window to remove distro-info and then simply run pip install distro-info==1.0.

Thank you for all the answers. To answer my own question, I was finally able to fix the issue by updating all the required packages.
Now there are no updates needed, and the app works again.
0 updates can be applied immediately.
The list of available updates is more than a week old.
To check for new updates run: sudo apt update

Syntax Error from 'pip install' in python + command line

Okay, so, I'm running Python 3.4.3 with pip 9.0.1, with the setuptools and wheel.
I'm running this inside JetBrains PyCharm Professional 2017.2.3.
The issue I'm having is trying to install the twitter api packages from this tutorial (ya I'm a n00b) http://wiki.openhatch.org/Twitter
I'm struggling with installing the 4 dependencies mentioned in the first part of the tutorial (httplib2, simplejson, oauth2 and python-twitter)
Honestly, I'm just getting back into programming and this is a project I'd like to complete.
So, I need help with:
Installing pip, and how to use it, and where (python shell or command line or)
the dev.twitter.com website (and where to find what I need from there)
Any help is massively appreciated and sorry if I sound really n00by, but do correct me where I'm using incorrect terms etc because that's how I learn I guess :)

If you haven't got pip installed, find your python installation file.Execute it and choose 'Change Python Installation'. Now choose 'pip' to install and 'add python.exe to path'. Wait for it to finish. Now run windows command line and type:
pip install package_name
Sometimes you may experience that a package isn't available on pip or doesn't work.There are 2 common (not always working) ways to install a package without making pip download the file:
1) A package may be available as a .whl file for download.Download it.Now find it and copy its name .Open a command line in dictionary where it is located and type
pip install **now paste the filename and add .whl**'
2)A package is available as a zip file.Packages are often packed into a zip file.Download the file and extract it.Open a command line in it's directory.You may see setup.py file.Run
python setup.py install
When finished installing pip and adding python to path,you can run:
pip install httplib2 simplejson oauth2 python-twitter
Done.

Once you have pip installed, open the command prompt and just type pip install name_of_the_extension.
In this case, pip install httplib2 will install this package.
I believe you have pip installed on your computer, so it shouldn't be a problem to install the 4 packages you need.

How do I install a Python library? [duplicate]

I'm having a hard time setting up python packages. EasyInstall from SetupTools is supposed to help that, but they don't have an executable for Python 2.6.
For instance to install Mechanize, I'm just supposed to put the Mechanize folder in C:\Python24\Lib\site-packages according to INSTALL.txt, but runnning the tests does not work. Can someone help shed some light on this? Thanks!

The accepted answer is outdated. So first, pip is preferred over easy_install, (Why use pip over easy_install?). Then follow these steps to install pip on Windows, it's quite easy.
Install setuptools:
curl https://bootstrap.pypa.io/ez_setup.py | python
Install pip:
curl https://bootstrap.pypa.io/get-pip.py | python
Optionally, you can add the path to your environment so that you can use pip anywhere. It's somewhere like C:\Python33\Scripts.

Newer versions of Python for Windows come with the pip package manager. (source)
pip is already installed if you're using Python 2 >=2.7.9 or Python 3 >=3.4
Use that to install packages:
cd C:\Python\Scripts\
pip.exe install <package-name>
So in your case it'd be:
pip.exe install mechanize

This is a good tutorial on how to get easy_install on windows. The short answer: add C:\Python26\Scripts (or whatever python you have installed) to your PATH.

You don't need the executable for setuptools.
You can download the source code, unpack it, traverse to the downloaded directory and run python setup.py install in the command prompt

Starting with Python 2.7, pip is included by default. Simply download your desired package via
python -m pip install [package-name]

As I wrote elsewhere
Packaging in Python is dire. The root cause is that the language ships without a package manager.
Fortunately, there is one package manager for Python, called Pip. Pip is inspired by Ruby's Gem, but lacks some features. Ironically, Pip itself is complicated to install. Installation on the popular 64-bit Windows demands building and installing two packages from source. This is a big ask for anyone new to programming.
So the right thing to do is to install pip. However if you can't be bothered, Christoph Gohlke provides binaries for popular Python packages for all Windows platforms http://www.lfd.uci.edu/~gohlke/pythonlibs/
In fact, building some Python packages requires a C compiler (eg. mingw32) and library headers for the dependencies. This can be a nightmare on Windows, so remember the name Christoph Gohlke.

I had problems in installing packages on Windows. Found the solution. It works in Windows7+. Mainly anything with Windows Powershell should be able to make it work. This can help you get started with it.
Firstly, you'll need to add python installation to your PATH variable. This should help.
You need to download the package in zip format that you are trying to install and unzip it. If it is some odd zip format use 7Zip and it should be extracted.
Navigate to the directory extracted with setup.py using Windows Powershell (Use link for it if you have problems)
Run the command python setup.py install
That worked for me when nothing else was making any sense. I use Python 2.7 but the documentation suggests that same would work for Python 3.x also.

Upgrade the pip via command prompt ( Python Directory )
D:\Python 3.7.2>python -m pip install --upgrade pip
Now you can install the required Module
D:\Python 3.7.2>python -m pip install <<yourModuleName>>

pip is the package installer for python, update it first, then download what you need
python -m pip install --upgrade pip
Then:
python -m pip install <package_name>

You can also just download and run ez_setup.py, though the SetupTools documentation no longer suggests this. Worked fine for me as recently as 2 weeks ago.

PS D:\simcut> C:\Python27\Scripts\pip.exe install networkx
Collecting networkx
c:\python27\lib\site-packages\pip\_vendor\requests\packages\urllib3\util\ssl_.py:318: SNIMissingWarning: An HTTPS reques
t has been made, but the SNI (Subject Name Indication) extension to TLS is not available on this platform. This may caus
e the server to present an incorrect TLS certificate, which can cause validation failures. You can upgrade to a newer ve
rsion of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#snimissi
ngwarning.
SNIMissingWarning
c:\python27\lib\site-packages\pip\_vendor\requests\packages\urllib3\util\ssl_.py:122: InsecurePlatformWarning: A true SS
LContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL con
nections to fail. You can upgrade to a newer version of Python to solve this. For more information, see https://urllib3.
readthedocs.io/en/latest/security.html#insecureplatformwarning.
InsecurePlatformWarning
Downloading networkx-1.11-py2.py3-none-any.whl (1.3MB)
100% |################################| 1.3MB 664kB/s
Collecting decorator>=3.4.0 (from networkx)
Downloading decorator-4.0.11-py2.py3-none-any.whl
Installing collected packages: decorator, networkx
Successfully installed decorator-4.0.11 networkx-1.11
c:\python27\lib\site-packages\pip\_vendor\requests\packages\urllib3\util\ssl_.py:122: InsecurePlatformWarning: A true SSLContext object i
s not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. You can upgrade
to a newer version of Python to solve this. For more information, see https://urllib3.readthedocs.io/en/latest/security.html#insecureplat
formwarning.
InsecurePlatformWarning
Or just put the directory to your pip executable in your system path.

As mentioned by Blauhirn after 2.7 pip is preinstalled. If it is not working for you it might need to be added to path.
However if you run Windows 10 you no longer have to open a terminal to install a module. The same goes for opening Python as well.
You can type directly into the search menu pip install mechanize, select command and it will install:
If anything goes wrong however it may close before you can read the error but still it's a useful shortcut.

Python (anaconda) add packages with pip behind proxy

sorry for asking a probalby stupid question, however, I am completely new to setting up/installing python packages, i.e. I have never done it.
So far I installed anaconda3 and worked with the pre installed packages. Now I need the google api pyhon client.
I do not even know whether pip is installed in the anaconda package but I assume it.
What have I tried so far:
In Windows cmd:
1. pip install --upgrade google-api-python-client
2. pip install -- proxy="XXX.XXX.XX.X:XX" -- upgrade google-api-python-client
3. export https_proxy="...."
pip install --upgrade google-api-python-client
I get the following errors:
cannot fetch index base url https://pypi.python.org/simple
unknown command
unknown command
In addition I tried to download the google_api_python_client and unzipped it.
However, I do not know how to proceed here.
BTW: Here in my company we are still on XP
Any help would be highly appreciated!
THANK YOU

Would like to add to the answer by #alok-nayak that you should use the following:
python setup.py install
Leads to:
Installed ~/anaconda/lib/python2.7/site-packages/google_api_python_client-1.4.2-py2.7.egg

After unzipping google_api_python_client. You should run the setup.py file
python setup.py
Also you can edit ".condarc" file in your home folder, as explained here http://conda.pydata.org/docs/config.html . enter your proxy details there

Why is pip installing an old version of my package?

I've just uploaded a new version of my package to PyPi (1.2.1.0-r4): I can download the egg file and install it with easy_install, and the version checks out correctly. But when I try to install using pip, it installs version 1.1.0.0 instead. Even if I explicitly specify the version to pip with pip install -Iv tome==1.2.1.0-r4, I get this message: Requested tome==1.2.1.0-r4, but installing version 1.1.0.0, but I don't understand why.
I double checked with parse_version and confirmed that the version string on 1.2.1 is greater than that on 1.1.0 as shown:
>>> from pkg_resources import parse_version as pv
>>> pv('1.1.0.0') < pv('1.2.1.0-r4')
True
>>>
So any idea why it's choosing to install 1.1.0 instead?

This is an excellent question. It took me forever to figure out. This is the solution that works for me:
Apparently, if pip can find a local version of the package, pip will prefer the local versions to remote ones. I even disconnected my computer from the internet and tried it again -- when pip still installed the package successfully, and didn't even complain, the source was obviously local.
The really confusing part, in my case, was that pip found the newer versions on pypi, reported them, and then went ahead and re-installed the older version anyway ... arggh. Also, it didn't tell me what it was doing, and why.
So how did I solve this problem?
You can get pip to give verbose output using the -v flag ... but one isn't enough. I RTFM-ed the help, which said you can do -v multiple times, up to 3x, for more verbose output. So I did:
pip install -vvv <my_package>
Then I looked through the output. One line caught my eye:
Source in /tmp/pip-build-root/ has version 0.0.11, which satisfies requirement <my_package>
I deleted that directory, after which pip installed the newest version from pypi.

Try forcing download the package again with:
pip install --no-cache-dir --upgrade <package>

Thanks to Marcus Smith, who does amazing work as a maintener of pip, this was fixed in version 1.4 of pip which was released on 2013-07-23.
Relevant information from the changelog for this version
Fixed a number of issues (#413, #709, #634, #602, and #939) related to
cleaning up and not reusing build directories. (Pull #865, #948)

I found here that there is a known bug in pip that it won't check the version if there's a build directory with unpacked sources. I have checked this on my troubling package and after deleting its sources from build directory pip installed the required version.

If you are using a pip version that comes with some distribution packages (ex. Ubuntu python-pip), you may need to install a newer pip version:
Update pip to latest version:
sudo pip install -U pip
In case of "virtualenv", skip "sudo":
pip install -U pip
Following command may be required, if your shell report something like -bash: /usr/bin/pip: No such file or directory after pip update:
hash -d pip
Now install your package as usual:
pip install -U foo
or
pip install foo==package.version.here

Got the same issue to update pika 0.9.5 to 0.9.8. The only working way was to install from tarball: pip install https://pypi.python.org/packages/source/p/pika/pika-0.9.8.tar.gz.

In my case the python version used (3.4) didn't satisfy Django 2.1 dependencies requirements (python >= 3.5).

For my case I had to delete the .pip folder in my home directory and then I was able to get later versions of multiple libraries. Note that this was on linux.
pip --version
pip 18.1 from /usr/lib/python2.7/site-packages/pip (python 2.7)
virtualenv --version
15.1.0

Just in case that anyone else hassles with upgrading torchtext (or probably any other torch library):
Although https://pypi.org/project/torchtext/ states that you could run pip install torchtext I had to install it similiar to torch by specifying --find-links aka -f:
pip install torchtext===0.8.1 -f https://download.pytorch.org/whl/torch_stable.html
What irritated me was that PyCharm pointed me to the new version, but couldn't find it when attempting to upgrade to it. I guess that PyCharm uses its own mechanism to spot new versions. Then, when invoking pip under the hood, it didn't find the new version without the --find-links option.

In my case I am pip installing a .tar.gz package from Artifactory that I make a lot of updates to. In order to overwrite my cached Python files and always grab/install the latest I was able to run:
pip install --no-cache-dir --force-reinstall <path/to/tar.gz>
You should see this re-download any necessary files and install those, instead of using your local cache.

10 years on and pip still fails to work as expected 😖.
I wasted a couple of hours now banging my head against the wall trying to find out why pip won't install a development version of my package. In my case, there are versions 0.0.4 and 0.0.5.dev1 in a private gitlab.com package registry (hence the --extra-index-url argument below), but I believe that's not relevant to the problem.
Following a lot of the advice on this page, I create a test venv in a far away folder, clear the pip cache, uninstall the package in question, etc. first to rule out the most common problems:
$ pip cache purge && \
pip uninstall --yes my-package && \
pip install --extra-index-url "https://_:${GITLAB_PASSWORD_TOOLS_VAULTTOOLS}#gitlab.com/api/v4/projects/<project-id>/packages/pypi/simple" \
--no-cache-dir \
--pre \
--upgrade my-package
output (using empty lines to separate output for commands):
WARNING: No matching packages
Files removed: 0
Found existing installation: my-package 0.0.4
Uninstalling my-package-0.0.4:
Successfully uninstalled my-package-0.0.4
Looking in indexes: https://pypi.org/simple, https://_:****#gitlab.com/api/v4/projects/<project-id>/packages/pypi/simple
Collecting my-package
Downloading https://gitlab.com/api/v4/projects/<project-id>/packages/pypi/files/f07 ... 397/my_package-0.0.5.dev1-py3-none-any.whl (16 kB)
Downloading https://gitlab.com/api/v4/projects/<project-id>/packages/pypi/files/775 ... 70e/my_package-0.0.4-py3-none-any.whl (16 kB)
...
Successfully installed my-package-0.0.4
So pip does see the dev package version, but chooses the earlier one nonetheless.
In an attempt to figure out what's going on, I published a 0.0.5 version: Error persists, pip sees all three versions, but still installs 0.0.4.
In a further, increasingly desperate attempt, I removed any versions prior to 0.0.5* from the gitlab.com package registry.
Only now, pip would bother to actually display some useful information:
$ (same command as above)
... (similar output as above) ...
ERROR: Cannot install my-package==0.0.5 and my-package==0.0.5.dev1 because these package versions have conflicting dependencies.
The conflict is caused by:
my-package 0.0.5 depends on my-other-package<0.2.5 and >=0.2.4
my-package 0.0.5.dev1 depends on my-other-package<0.2.5 and >=0.2.4
To fix this you could try to:
1. loosen the range of package versions you've specified
2. remove package versions to allow pip attempt to solve the dependency conflict
ERROR: ResolutionImpossible: for help visit https://pip.pypa.io/en/latest/topics/dependency-resolution/#dealing-with-dependency-conflicts
OK, so there is something wrong with my package dependencies. Thanks for letting me know.
Seriously - I tried hard for a couple of hours using all kinds of pip ... -vvv and/or fixed versions such as e.g. my-package==0.0.5.dev1 - but I did not manage to get any useful output out of pip - until I wiped the entire history from my package registry 🤬.
Hope this at least helps someone in the same situation.

I found that if you use microversions, pip doesn't seem to recognize them. For example, we couldn't get version 1.9.9.1 to upgrade.

In my case, someone had published the latest version of a package with python2, so attempting to pip3 install it grabbed an older version that had been built with python3.
Handy things to check when debugging this:
If pip install claims to not be able to find the version, see whether pip search can see it.
Take a look at the "Download Files" section on the pypi repo -- the filenames might suggest what's wrong (in my case i saw -py2- there clear as day).
As suggested by others, try running pip install --no-cache-dir in case pip isn't bothering to ask the internet because it already has your answer locally.

I had hidden unversioned files under the Git tab in PyCharm that were being installed with pip install . even though I didn't see the files anywhere else.
Took a long time to find it for me, posting this in hope that it'll help somebody else.

if you need the path for your package do pip -v list. Example see related post when using pip -e Why is an old version of a package of my python library installing by itself with pip -e?