Add Check If Package Is Installed With Pip as a Python TIL

python/check-if-package-is-installed-with-pip.md

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+# Check If Package Is Installed With Pip
+
+I recently installed PyTorch, but when I tried using it, I was getting an error
+about `numpy` not being installed. I was kind of surprised by that because I
+thought I would have already had that.
+
+I wanted to check, so I asked with `pip show`:
+
+```bash
+❯ python3 -m pip show numpy
+WARNING: Package(s) not found: numpy
+```
+
+I can even list everything that is installed with `pip` using `pip list` like
+so:
+
+```bash
+❯ python3 -m pip list
+Package            Version   Build
+------------------ --------- -----
+certifi            2026.1.4
+cffi               2.0.0
+charset-normalizer 3.4.4
+click              8.3.1
+commonmark         0.9.1
+cryptography       46.0.3
+docutils           0.22.4
+filelock           3.24.2
+fsspec             2026.2.0
+idna               3.11
+Jinja2             3.1.6
+...
+```
+
+I then installed `numpy` (`python3 -m pip install numpy`) and how I can use `pip
+show` again to confirm that.
+
+```bash
+❯ python3 -m pip show numpy
+Name: numpy
+Version: 2.4.2
+Summary: Fundamental package for array computing in Python
+Home-page: https://numpy.org
+Author: Travis E. Oliphant et al.
+Author-email:
+License-Expression: BSD-3-Clause AND 0BSD AND MIT AND Zlib AND CC0-1.0
+Location: /Users/lastword/.local/share/mise/installs/python/3.12.12/lib/python3.12/site-packages
+Requires:
+Required-by:
+```