Develop Reference

Can I find the URL from which pip installs packages

Is there a way to retrieve the URL of package installed by pip?
For example, I want the URL of Cython 0.29.19 for arm64 installed by pip3 install Cython==0.29.19

You can search the packages on https://pypi.org.
pip installs packages from there.
You can manually download the file and load it to your local Python installation using pip.
Here is the link for cython:
https://pypi.org/project/Cython/#files

Where do I find the "get-pip.py" dowload link?

I as part of a tutorial am trying to download pip.py but the link is different now and I can't find a button which I can download pip.
This is the link I get: https://pip.pypa.io/en/stable/installing/#cmdoption-no-setuptools
Anyone know where I can find the download?

Did you read the docs? ie:
Do I need to install pip? pip is already installed if you are using
Python 2 >=2.7.9 or Python 3 >=3.4 downloaded from python.org or if
you are working in a Virtual Environment created by virtualenv or
pyvenv. Just make sure to upgrade pip.
Installing with get-pip.py To install pip, securely download
get-pip.py. [1]:
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py

How to install beautifulsoup into python3, when default dir is python2.7?

I have both Python 2.7 and Python 3.5 installed. When I type pip install beautifulsoup4 it tells me that it is already installed in python2.7/site-package directory.
But how do I install it into the python3 dir?

I think pip3 will satisfy your needs, use the below command on the terminal:
pip3 install beautifulsoup4
See doc

Run as root:
apt-get install python3-bs4
#or
pip3 install beautifulsoup4
Afterwards import it like this:
import bs4

If you’re using a recent version of Debian or Ubuntu Linux, you can install Beautiful Soup with the system package manager:
$ apt-get install python-bs4 (for Python 2)
$ apt-get install python3-bs4 (for Python 3)
Afer install import the library
from bs4 import BeautifulSoup

The package is bs4 and can be installed with following command:
python -m pip install bs4

I had some mismatch between Python version and Beautifulsoup. I was installing this project
Th3Jock3R/LinuxGSM-Arma3-Mod-Update
to a linux centos8 dedicated Arma3 server. Python3 and Beautifulsoup4 seem to match.So I updated Python3, removed manually Beautifulsoup files and re-installed it with: sudo yum install python3-beautifulsoup4 (note the number 3). Works. Then pointing directories in Th3Jock3R:s script A3_SERVER_FOLDER = "" and A3_SERVER_DIR = "/home/arma3server{}".format(A3_SERVER_FOLDER) placing and running the script in same folder /home/arma3server with python3 update.py. In this folder is also located new folder called 'modlists' Now the lightness of mod loading blows my mind. -Bob-

If you are on windows, this works for Python3 as well
py -m pip install bs4

installation lxml package Python

I cant install lxml package for python scraping. I installed required lbraries C http://users.skynet.be/sbi/libxml-python/ . Tryed it with python 2.7 2.7 3.4 . dowsnt work still cant install my lxml package .

Use the required .whl file from any source Example and use pip.
pip install "location where .whl is saved"
Pip can be found in PYTHONHOME/Scripts. pip is available by default from 2.7.10

How to install third-party modules on python3

There are several versions of python on my mac OS X system.
I just installed beautiful soup4 on python2.7.6, but how can I install the same module on the version 3.4.3?

From the BeautifulSoup Official Documentation:
Beautiful Soup 4 is published through PyPi, so if you can’t install it
with the system packager, you can install it with easy_install or pip.
The package name is beautifulsoup4, and the same package works on
Python 2 and Python 3.
$ easy_install beautifulsoup4
$ pip install beautifulsoup4

You should always use a virtualenv. For each project, install the requirements you need inside that project's own virtualenv.