How to find the exact location of a method in Python source code?

Question

So in an iPython terminal, if you type a method followed by ?? you will get the source code and its location:

In [1]: import numpy as np

In [2]: np.angle??

Source:
@array_function_dispatch(_angle_dispatcher)
def angle(z, deg=False):
    z = asanyarray(z)
    if issubclass(z.dtype.type, _nx.complexfloating):
        zimag = z.imag
        zreal = z.real
    else:
        zimag = 0
        zreal = z

    a = arctan2(zimag, zreal)
    if deg:
        a *= 180/pi
    return a
File:      ~/Documents/venv_global/lib/python3.8/site-packages/numpy/lib/function_base.py
Type:      function

How would I find the location of the source code (+the line number of the method) without entering into iPython.

PS: (Removed the docstring from the output for readability).

Edit:

I am looking for something like a subcommand that I can run which would give the information without needing to enter the shell. Not sure if it is possible though but it would look something like this:

ipython --source numpy.angle

Does this answer your question? [How can I get the source code of a Python function?](https://stackoverflow.com/questions/427453/how-can-i-get-the-source-code-of-a-python-function) — TankorSmash, Nov 20 '20 at 19:20
@TankorSmash That was the question that I looked at before posting. All of them require you to enter a terminal. — Al-Baraa El-Hag, Nov 20 '20 at 19:57
What do you mean? You need to run python to execute python code. `inspect.getsource(foo) ` gives you the source, no? — TankorSmash, Nov 20 '20 at 20:01
@TankorSmash I was looking for a subcommand that I can add to iPython that will give it to me without having to enter the shell. For example: `ipython --source numpy.angle`. Though I do not know if it is possible — Al-Baraa El-Hag, Nov 20 '20 at 20:03

Prayson W. Daniel · Accepted Answer · 2020-11-20T20:17:02.743

1

What you are seeing is a docstring and source documentations and file path:

import inspect
import numpy as np

print(np.angle.__doc__)
print('Source:')
print(inspect.getsource(np.angle))
print('File:')
print(inspect.getsourcefile(np.angle))
print('Type:')
print(type(np.angle))

The above code prints the docstrings, the source file path and type you get from ?? in iPython.

edited Nov 20 '20 at 20:17

answered Nov 20 '20 at 20:04

Prayson W. Daniel

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I believe that `??` in iPython goes one step further and gives you the location of the method. – Al-Baraa El-Hag Nov 20 '20 at 20:12
I added that too. Use `inspect` to get extra details – Prayson W. Daniel Nov 20 '20 at 20:14
The `inspect.getsourcefile(np.angle)` gives me `'<__array_function__ internals>'` not the exact file location. But you can add on to your answer `inspect.getsourcelines(np.angle)[1]` – Al-Baraa El-Hag Nov 20 '20 at 20:22
Also, is there a way to run this without opening a python terminal? – Al-Baraa El-Hag Nov 20 '20 at 20:22
Yes, instead on new line replaced above with `;` and the run in terminal `python -c "import inspect;import numpy as np;#..." – Prayson W. Daniel Nov 21 '20 at 03:55
I see, I assume I would have to write it as a bash script that takes arguments for it to work. I'll accept your answer – Al-Baraa El-Hag Nov 21 '20 at 13:16

How to find the exact location of a method in Python source code?

1 Answers1