Unable to disable creation of __pycache__ and .pyc files

[kpyeri]

When I install a package using pip, I would like to disable the creation of __pycache__ folders and .pyc files. I tried option -B with python and --no-cache-dir with pip but this does not prevent creation of these files/folders. Is anything else required for this to work?

Output:
(foo) [user@centos75 test]$ python -V
Python 3.6.3
(foo) [user@centos75 test]$ which python
/opt/test/foo/bin/python
(foo) [user@centos75 test]$ ll /opt/test/foo/bin/python
lrwxrwxrwx. 1 user user 39 Oct  3 11:45 /opt/test/foo/bin/python -> /opt/rh/rh-python36/root/usr/bin/python
(foo) [user@centos75 test]$ find foo -name *.pyc | grep idna
(foo) [user@centos75 test]$ python -I -B -m pip install idna --disable-pip-version-check --no-cache-dir
Collecting idna
  Downloading https://files.pythonhosted.org/packages/4b/2a/0276479a4b3caeb8a8c1af2f8e4355746a97fab05a372e4a2c6a6b876165/idna-2.7-py2.py3-none-any.whl (58kB)
    100% |¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦| 61kB 2.2MB/s 
Installing collected packages: idna
Successfully installed idna-2.7
(foo) [user@centos75 test]$ find foo -name *.pyc | grep idna
foo/lib/python3.6/site-packages/idna/__pycache__/__init__.cpython-36.pyc
foo/lib/python3.6/site-packages/idna/__pycache__/codec.cpython-36.pyc
foo/lib/python3.6/site-packages/idna/__pycache__/compat.cpython-36.pyc
foo/lib/python3.6/site-packages/idna/__pycache__/core.cpython-36.pyc
foo/lib/python3.6/site-packages/idna/__pycache__/idnadata.cpython-36.pyc
foo/lib/python3.6/site-packages/idna/__pycache__/intranges.cpython-36.pyc
foo/lib/python3.6/site-packages/idna/__pycache__/package_data.cpython-36.pyc
foo/lib/python3.6/site-packages/idna/__pycache__/uts46data.cpython-36.pyc
(foo) [user@centos75 test]$ 

[Larz60+]

pip (i believe) uses gc. You can read about it here: https://docs.python.org/3.7/library/gc.html#module-gc
there are arguments that you can include to modify behavior, but now you're messing with things you really shouldn't touch and I wouldn't go there.
I rarely look at site-packages. Perhaps use something like bleachbit, but again, you better know exactly what you are doing.

My suggestion: don't look at site packages, if you want to know what's installed with pip, use

pip list