Specific reasons to favor pip vs. conda when installing Python packages

Question

I use miniconda as my default python installation. What is the current (2019) wisdom regarding when to install something with conda vs. pip?

My usual behavior is to

Answer 1

Note: The following recommendations are now part of the official documentation.

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"What is the current (2019) wisdom regarding when to install something with conda vs. pip?"

Anaconda Inc's Jonathan Helmus sums this up quite nicely in the post "Using Pip in a Conda Environment." Here's an excerpt from the final best practices recommendation:

Best Practices Checklist

Use pip only after conda

• install as many requirements as possible with conda, then use pip
• pip should be run with --upgrade-strategy "only-if-needed" (the default)
• Do not use pip with the --user argument, avoid all “users” installs

Use Conda environments for isolation

• create a Conda environment to isolate any changes pip makes
• environments take up little space thanks to hard links
• care should be taken to avoid running pip in the root [base] environment

Recreate the environment if changes are needed

• once pip has been used conda will be unaware of the changes
• to install additional Conda packages it is best to recreate the environment

Store conda and pip requirements in text files

• package requirements can be passed to conda via the --file argument
• pip accepts a list of Python packages with -r or --requirements
• conda env will export or create environments based on a file with conda and pip requirements