Zintis' pip cheat sheet

For my mac osx python, I had to use python3 -m pip install --upgrade pip because python actually ran python 2.7, where python3 ran python 3.9.1.

From docs.ansible.com :

$ curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
$ python get-pip.py --user

ansible@c8host /home/ansible[1011] $
pip3.8 list
Package    Version
---------- -------
pip        20.1.1
setuptools 47.1.0
WARNING: You are using pip version 20.1.1; however, version 20.2.2 is available.
You should consider upgrading via the '/usr/local/bin/python3.8 -m pip install --upgrade pip' command.
ansible@c8host /home/ansible[1012] $
python3.8 -m pip install --upgrade pip
Defaulting to user installation because normal site-packages is not writeable
Collecting pip
  Using cached pip-20.2.2-py2.py3-none-any.whl (1.5 MB)
Installing collected packages: pip
Successfully installed pip-20.2.2
WARNING: You are using pip version 20.1.1; however, version 20.2.2 is available.
You should consider upgrading via the '/usr/local/bin/python3.8 -m pip install --upgrade pip' command.
ansible@c8host /home/ansible[1013] $

With Python installed, you also got pip, or Python Install Packages These "packages" are really modules. For example requests, json,

Common pip commands are:

pip help
pip help install
pip search meraki
pip install package
pip install meraki
pip install --upgrade package
pip install -U package
pip install -U pip     *** important to keep pip up to date (security)
pip install -r ~requirements.txt~   # which is a text file of python modules
pip uninstall package
pip freeze  # to list all the packages in ~requirements.txt~ format
pip list    # same thing but not in requirements format, but with options
pip list --outdated
pip list -o  (same thing)

Could be one of the following:

1. /usr/bin/env pip
2. pip
3. python3 -m pip
4. pip3.8
5. seems like the safest way to know which pip you are running is to use 3)

I use pip freeze to list them. As of May 2nd, 2019 my pip freeze is: Last login: Wed May 1 21:27:04 on ttys000 /Users/zintis[2] % pip freeze

If you have installed python, but which pip comes up empty, you may have to brew unlink python followed by brew link python to fix it.

.
/Users/zintis/eg[70] % brew unlink python
Unlinking /usr/local/Cellar/python/3.7.4... 24 symlinks removed
/Users/zintis/eg[71] % brew link python
Linking /usr/local/Cellar/python/3.7.4... 24 symlinks created
/Users/zintis/eg[72] % which pip
pip: Command not found.
/Users/zintis/eg[73] % 

The above unlink did not work but all I had to do was reboot my macbook. Then I got:

/Users/zintis[1] % which pip
/Users/zintis/.pyenv/shims/pip
/Users/zintis/eg[73] % 

Usually, the requirments.txt, if present, was included in the downloaded python module if that module had any prerequisites. This way the module can ensure that all prerequisites are also installed.

See the section on virtual environments to see how to create the requirements.txt for your own projects. (I can use org-mode to add a link to this section within this same file, but I don't quite know how. .. will fix this at a later date.)

When the modules you want pip to install are not in the usual Pypi site, you must download them to a folder and then … what? Check out stackoverflow.com on this topic.

That was as good reference site, but in the end, I had to run the setup.py script in the root directory of the downloaded cobra folder, like so:

Here is an example of a pip install with errors, and subsequent corrections:

= /Users/zintis/bin[11] % pip install –upgrade virtualenv Collecting virtualenv Downloading https://files.pythonhosted.org/packages/4f/ba/6f9315180501d5ac3e707f19fcb1764c26cc6a9a31af05778f7c2383eadb/virtualenv-16.5.0-py2.py3-none-any.whl (2.0MB)

Installing collected packages: virtualenv Found existing installation: virtualenv 16.4.3 Uninstalling virtualenv-16.4.3: ERROR: Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: 'zip-safe' Consider using the `–user` option or check the permissions.

/Users/zintis/bin[12] % pip install –upgrade –user virtualenv Collecting virtualenv Using cached https://files.pythonhosted.org/packages/4f/ba/6f9315180501d5ac3e707f19fcb1764c26cc6a9a31af05778f7c2383eadb/virtualenv-16.5.0-py2.py3-none-any.whl Installing collected packages: virtualenv Successfully installed virtualenv-16.5.0

Pip install documention on pip.pypa.io

This doc.python-guide.org link has some good explanation of additional info. Worth the read. specifically on pipenv, a virtual environment package manager for python modules.

• pip in virtualenv (python2 or python3)
• venv (python3)

First pip freeze gave me this list, with which I highlight what is added when I install pipenv:

new already satisfied

- appdirs==1.4.4

• appnope==0.1.2
• backcall==0.2.0
• beautifulsoup4==4.9.3

- certifi==2020.11.8

• chardet==3.0.4
• cycler==0.10.0
• decorator==4.4.2

- distlib==0.3.1 - filelock==3.0.12

• flake8==3.8.4
• idna==2.10
• ipython==7.19.0
• ipython-genutils==0.2.0
• jedi==0.17.2
• kiwisolver==1.3.1
• matplotlib==3.3.3
• mccabe==0.6.1
• numpy==1.19.4
• pandas==1.1.4
• parso==0.7.1
• passlib==1.7.4
• pexpect==4.8.0
• pickleshare==0.7.5
• Pillow==8.0.1

- pipenv==2020.11.15

• prompt-toolkit==3.0.8
• ptyprocess==0.6.0
• pycodestyle==2.6.0
• pyflakes==2.2.0
• Pygments==2.7.2
• pyparsing==2.4.7
• python-dateutil==2.8.1
• pytz==2020.4
• requests==2.25.0
• scipy==1.5.4

- six==1.15.0

• soupsieve==2.0.1
• traitlets==5.0.5
• urllib3==1.26.2

- virtualenv==20.2.2 - virtualenv-clone==0.5.4

• wcwidth==0.2.5

This is what I did: /bin/python/venv-webdev/bin/python -m pipenv install requests

/Users/zintis/bin/python/mynewpythproject[532]:
$ ~/bin/python/venv-webdev/bin/python -m pipenv install  requests
Creating a virtualenv for this project...
Pipfile: /Users/zintis/bin/python/mynewpythproject/Pipfile
Using /usr/local/bin/python3 (3.9.0) to create virtualenv...
⠋ Creating virtual environment...created virtual environment CPython3.9.0.final.0-64 in 726ms
  creator CPython3Posix(dest=/Users/zintis/.local/share/virtualenvs/mynewpythproject-F9bljqZV, clear=False, no_vcs_ignore=False, global=False)
  seeder FromAppData(download=False, pip=bundle, setuptools=bundle, wheel=bundle, via=copy, app_data_dir=/Users/zintis/Library/Application Support/virtualenv)
    added seed packages: pip==20.3.1, setuptools==51.0.0, wheel==0.36.1
  activators BashActivator,CShellActivator,FishActivator,PowerShellActivator,PythonActivator,XonshActivator

✔ Successfully created virtual environment! 
Virtualenv location: /Users/zintis/.local/share/virtualenvs/mynewpythproject-F9bljqZV
Creating a Pipfile for this project...
Installing requests...
Adding requests to Pipfile's [packages]...
✔ Installation Succeeded 
Pipfile.lock not found, creating...
Locking [dev-packages] dependencies...
Locking [packages] dependencies...
Building requirements...
Resolving dependencies...
✔ Success! 
Updated Pipfile.lock (fe5a22)!
Installing dependencies from Pipfile.lock (fe5a22)...
  🐍   ▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉▉ 0/0 — 00:00:00
To activate this project's virtualenv, run pipenv shell.
Alternatively, run a command inside the virtualenv with pipenv run.
/Users/zintis/bin/python/mynewpythproject[533]:
$ 

As you can see, it looks like 3.9 was used, but directly, through /usr/local/bin/python3 which I checked afterward was a symlink to /usr/local/Cellar/python@3.9/3.0.0₁/bin/python3

What the /bin/python/venv-webdev/bin/python -m pipenv install requests command created:

/Users/zintis/bin/python/mynewpythproject[535]:
$ tree
.
├── Pipfile
└── Pipfile.lock

0 directories, 2 files
/Users/zintis/bin/python/mynewpythproject[536]:

If you read the output above carefully, you see that it is in: Users/zintis.local/share/virtualenvs/mynewpythproject-F9bljqZV

You can cd to this directory and manually activate the virtual env, but you do not have to. It is much easier to cd into the project directory then run pipenv shell or pip run myscript.py if you want to just run this one script in this virtual environment.

To activate this project's virtualenv, run pipenv shell. Alternatively, run a command inside the virtualenv with pipenv run.

Do NOT use deactivate. Rather remember that pipenv shell command has put you into a subshell, and that subshell should be exited with the command exit.

If you do run deactivate, it will change your prompt just like the oldschool way, but it will NOT exit your subshell. So remember, just use plain old exit

If this is the 1st time creating a new virtual environment, you will create these two files, automatically.

1. Pipfile
2. pipfile.lock

As mentioned the Pipfile is just like a requirements.txt, but in a TML file very similar to a YAML file, but without the need for strict indentation.

Pipfile will let you specify a specific version of a package, or if you say "*" then pipenv will keep this package to the latest version.

If you need to keep an exact (even if slightly out of date) version, tnen you can see the pipfile.lock.

pipfile.lock

Will explicitly specify what version of each package is needed. It does that by comparing the SHA hash of the package. This pipfile.lock should NOT be edited directly. The commands pipenv lock command will "lock" this versions in place. You can then expllicitly update the lock (which updates the versions of each of the plackages according to what is "current" in the pipenv as of that moment.