I recently installed Anaconda on Arch Linux from the Arch repositories. By default, it was set to Python3, whereas I would like to use Python2.7. I followed the Anaconda documentation to create a new Python2 environment. Upon running my Python script which uses Numpy, I got the error No module named NumPy. I found this rather strange, as one of the major points of using Anaconda is easy installation of the NumPy/SciPy stack...
Nevertheless, I ran conda install numpy and it installed. Now, I still cannot import numpy, but when I run conda install numpy it says it is already installed. What gives?
Output of which conda: /opt/anaconda/envs/python2/bin/conda
Output of which python: /opt/anaconda/envs/python2/bin/python
The anaconda package in the AUR is broken. If anyone encounters this, simply install anaconda from their website. The AUR attempts to do a system-wide install, which gets rather screwy with the path.
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I have a Windows 7 machine running Python 3.8.5 with a very large number of physics/electronics/data analysis/simulation packages. As it turned out, I must have - for some inexplicable reason - installed the 32-bit version of Python instead of the 64-bit one despite having a 64-bit system. And I didn't notice until very recently when I was trying to install some packages that require 64-bit Python. Hence I've now downloaded and installed the latest Python version that is supported by Windows 7, which seems to be 3.8.10.
Question: What is the easiest and also fail-safe way to reinstall all the user packages - that I currently have under 3.8.5 - to 3.8.10?
For some reason, I couldn't find any "canonical" solution for this online. As it seems, Python does not come with any built-in support for updating or system migration and I'm honestly wondering why...
Anyway, my first idea was to get a list of all user (= "local"?) packages currently installed under 3.8.5, but I don't know how. Reason: Doing help('modules') inside the interpreter will list all packages and I don't see a way to "selectively apply" pip to a specific Python version, e.g. something like python-3.8.5 -m pip list --local is not supported.
After getting a list of the user packages, I was thinking to pack it into a batch command pip install package_1 package_2 <...> package_N, thus reinstalling everything to Python 3.8.10. And afterwards uninstalling Python 3.8.5 and removing all environment variables from system PATH.
Is this the proper way to do this?
Anyway, my first idea was to get a list of all user (= "local"?) packages currently installed under 3.8.5, but I don't know how.
Create a list of installed packages with pip freeze > pkglist.txt or pip list --format=freeze. If you already have one, that's great.
Then uninstall 32-bit Python 3.8.5 and clean your path for all Python related variables. Now, install 64-bit Python 3.8.10.
After reinstalling, you can install back all the packages with pip install -r pkglist.txt and it will restore the exact versions of the packages.
If you insist on having both 32-bit and 64-bit versions installed and also have the Python Launcher installed, you could invoke 32 and 64 bit versions separately with py -3.8-64 -m pip and py -3.8-32 -m pip.
I don't see a way to "selectively apply" pip to a specific Python version.
This is possible with the Python Launcher on Windows. But only between major/minor versions and not the patch versions according to its help message.
I would also recommend creating a virtual environment this time before installing the packages and leaving the root environment alone. You can create one named venv with just python -m venv venv, activate it with ./venv/Scripts/activate and proceed with the installation of packages.
Nope, doesn't work. After installing the packages with the newer Python version in PATH, e.g. Jupyter won't start.
If the Jupyter error persists, you could try pinning packages to their most recent patch/minor versions to update them and yet not break your code.
As a last resort, you could try installing Python 3.10 alongside your current Python installation (without uninstall or editing the PATH) and then installing the absolute latest versions of the packages in a 3.10 virtual environment to see if it works for you. You would invoke the two versions with Py Launcher, e.g. py -3.10 and py -3.8.
If I understood correctly, you have multiple packages like NumPy, pandas etc. installed on your machine, and you want to reinstall them "automatically" on a fresh installation of python.
The method (I use) to perform such an operation is by creating a file named setup.py which includes a list of all the packages.
Bellow, I am attaching an example of such a file I use in one of my projects:
from setuptools import setup, find_packages
setup(
name='surface_quality_tools',
version='0.1',
install_requires=["matplotlib", "psutil", "numpy", "scipy", "pandas", "trimesh", "pyglet", "networkx", "protobuf",
"numpy-stl", "sklearn", "opencv-python", "seaborn", "scikit-image", "flask", "tqdm", "pytest"],
package_data={'': ['*.json']},
packages=find_packages(include=[])
)
to run the installation you should open a command prompt from inside the project directory and run:
pip install -e .
You can find a nice example in this blog page
One common way of handling packages in Python is via virtual environments. You can use Anaconda (conda), venv or any of several other solutions. For example, see this post:
https://towardsdatascience.com/virtual-environments-104c62d48c54#:~:text=A%20virtual%20environment%20is%20a,a%20system%2Dwide%20Python).
The way this works in by keeping the Python interpreter separate from the virtual environment that contains all the necessary packages.
Probably the main reason Python doesn't feature migration tools (at least as part of standard library) is because pip - the main package tool - doesn't handle conflict resolution all too well. When you update a version of Python it might so happen (especially with niche packages) that some of them won't work any more and pip often won't be able to solve the dependencies. This is why it's a good idea to keep a separate venv for different Python versions and different projects.
The other tool you could use for easy migration is Docker which is a semi-virtual machine working on top of your host OS and containing usually some linux distribution, Python along with the necessary packages necessary for running and development.
It takes a bit of time to set up a container image initially but afterwards setting everythin on a new machine or in the cloud becomes a breeze.
Listing currently installed packages is done via pip freeze command, the output of which you can then pipe into a file to keep a record of project requirements, for example pip freeze > requirements.txt.
I have noticed that when I install new modules using pip install example, it installs correctly but when I try importing it in a script it says: ModuleNotFoundError: No module named 'example'. To get the modules working I have to copy the module's folder to the directory of my script. Before this started happening I had installed some modules which also work now so I'm a bit confused.
I'm guessing that there's something wrong with some PATH but I'm not really sure. How can I fix this?
Edit: I'm almost 100% sure that these problems started happening when I installed Anaconda. I have made sure Anaconda's folder is added to PATH but I still have the same issue.
With Anaconda, you would benefit from installing new packages by conda install example instead of using pip.
However, it is likely that you have installed another copy of Python that comes with Anaconda, and you should check which Python you are using by typing python -V in your command prompt or checking where it is installed (for Windows machines, check here). You might have installed the package to use with one version of Python, but your system directed you to the other one.
I have uninstalled my standalone Python distribution after installing Anaconda, so my default version of Python is the version that comes with Anaconda.
I am trying to set and install some packages with python. I have already installed python3 along with Anaconda.
My first question is that when I type:
$ python3
Anaconda says: "$" is not an internal or external command. Should I be using a different command or how can I fix this?
My second question is this: I am trying to install the packages from these four sites based on a book I got:
NumPy: http://docs.scipy.org/doc/numpy-1.10.1/user/install.html
SciPy: http://www.scipy.org/install.html
scikit-learn: http://scikit-learn.org/stable/install.html
matplotlib: http://matplotlib.org/1.4.2/users/installing.html
This note was in there as well: "If you are on Windows, you should have installed a SciPy-stack compatible version of Python 3".
When I go to copy the line for installing the packages on windows and pasting it into my terminal, it gives the error: "The system can not find the file specified"
How can I fix this?
Don't type the $, just python3.
The packages you mention are already included in Anaconda python distribution.
$ is usually used to indicate the start of a line that should be executed in a terminal window. So, therefore, remove the $ and write everything that comes afterwards.
If you installed Anaconda, then you should have the conda command available to you. Besides scikit-learn, the packages should already be installed with your Anaconda distribution. What you could do is $ conda install scikit-learn and this should install scikit-learn for you.
I recommend you to look at the documentation of Anaconda at the Anaconda website (https://docs.anaconda.com/anaconda/) to learn more on how Anaconda, packages and Python works.
Just as emmv said, a few other things in my mind:
You installed Python with Anaconda. I assume you did not add Python to PATH. You should check Anaconda website for any further installments, downloads etc.
Anaconda uses a simple "conda" command, after all. Really, just look at Anaconda's website if you are confused.
I'm trying to install numpy, matplotlib, and scipy in the right python version.
Initially I was testing with different python versions (3.2, 2.7, 2.6).
I removed all these versions using: How to uninstall Python 2.7 on a Mac OS X 10.6.4?
Afterwards, I reinstalled Python 2.7.11.
when I try to install numpy, matplotlib and scipy, using pip, I get the following message:
Requirement already satisfied (use --upgrade to upgrade) ...
In my terminal, I tried the following:
$ which python
/Library/Frameworks/Python.framework/Versions/2.7/bin/python
$ python
Python 2.7.11 (v2.7.11:.....)
.....
>>> import numpy
ImportError: No module named numpy
$ /System/Library/Frameworks/Python.framework/Versions/2.7/bin/python
Python 2.7.10 (default, ......
.....
>>> import numpy
>>> numpy.__version__
'1.8.0rc1'
for some reason these packages got installed in 2.7.10 and not 2.7.11, which is the version I downloaded from python.org. Also, I don't even know how I got the 2.7.10 version.
How can I fix this issue?
You can also use macports (https://www.macports.org/) to install different versions of python, numpy, and matplotlib. It's really quite simple.
Alternatively, you can perhaps use anaconda (https://www.continuum.io/downloads), which uses conda, to achieve your goal.
I recommend using virtualenv (with virtualenvwrapper: https://virtualenvwrapper.readthedocs.org). It is very easy to setup and you'll have absolutely no problems in future when you deal with multiple Python installations.
I work with virtualenv for years now and create for each project a separate virtual environment, which is always clean and I never have to deal with PATH, PYTHONPATH or whatever.
If you followed the virtualenvwrapper installation guide, you can simply create for example one virtualenv for everyday work via:
mkvirtualenv common -p /Library/Frameworks/Python.framework/Versions/2.7/bin/python
this will create the virtualenv and automatically activate it, so you can instantly install the packages you want:
pip install matplotlib numpy scipy
and every time you want to use it you type:
workon common
As you see above, you can specify the python executable via the -p flag. Each virtualenv will be a completely fresh and independent Python installation where you can use pip to install whatever you want (without root access of course).
It is likely to mean that you used pip or easy_install from another python version.
When you install your modules, make sure to use the correct pip version.
It might be /usr/local/bin/pip2.7 for example.
If you install Anaconda from continuum.io, you'll get access to versions of many packages that have been tested to work with the version of Python that you are interested in working with. Here's the list that come with the current version of their distribution.
You also get access to conda, which is a package and environment manager. Think pip + virtualenv.
Once you have that, you can do
conda create -n my_env python=3.6 numpy pandas
This will install Python 3.6 and all of the dependencies for numpy and pandas into a virtual environment called my_env. Conda will make sure that you have the most up to date packages that work together.
To access your environment, you can do:
activate my_env
Now you're running Python in that environment with those installed packages. If you need more packages, you can either do conda install package_name. If conda can't find the package, you can still do pip install package_name.
Note that as an added bonus, you get an optimized and pre-compiled version of Numpy by way of the Intel MKL.
(From my comment on a previous answer)
I'd second the recommendation for going the Anaconda route.
Particularly if you're using Numpy or anything that depends on Numpy
(Pandas, Scipy, Sci-kit Learn). Continuum has access to the Intel MKL
which gives you significant optimizations and pre-compiled C code
specific to your operating system. docs.continuum.io/mkl-optimizations
Anaconda Spyder is supposed to include numpy, scipy etc with the installation. Someone has installed Spyder for me on Windows 7 but if I try to import numpy or scipy , I get this error:
import numpy as np
ImportError: No module named numpy
I also can't run "conda" on the console.
What's wrong? What should I do to fix this? I tried adding PYTHONPATH in environment variables but no difference.
How can I check if they're even installed? I searched for NumPy in the computer, I only found the following:
It sounds like someone installed just spyder, not Anaconda, which is a separate thing (Anaconda is a collection of several Python packages, including Spyder, NumPy, and SciPy). Try downloading and installing Anaconda and using the Spyder that comes with that.
The thing is you have to install python 2.7. Surely you have a different python installed. If you download and install Python 2.7 this should works. Other thing you can do is search for the Anaconda Spyder version that support the Python you have installed.
It's probably that your the python core version of your spyder environment is different from the conda python version.
Python core version of your spyder environment
Conda python version
So you should make them of the same version then the problem will be solved.