Although I am not able to review your PR, I can provide my comments here. These comments are not restricted to the PR review only though. There is some general feedback as well.
I liked your usage of f-strings in electric_field_due_to_single_charge.py file on lines 60 and 61. I learned a better and more efficient way (instead of concatenation) to combine strings with other data types upon reading your code.
In line 33, the r_mag case might better be handled with the delta function condition.
For your separation_vector (p,o) and magnitude (v) functions, it would improve readability if your docstrings contained information about parameters, like they do for other functions you have defined.
You might want to include if name == "main": main() for running the code with direct execution.
You uploaded your files separately. They should be uploaded in a single folder which then is submitted for a PR.
In your Electric_Field_due_to_single_charge.md file, there were a bunch of typos:
Your code had docstrings, algorithm, unit tests, and followed the HW guidelines.
The code ran successfully, however, the unit tests file showed a failure:
Although I am not able to review your PR, I can provide my comments here. These comments are not restricted to the PR review only though. There is some general feedback as well.