Rerun python program from terminal after making changes

Question

It is very nice and easy to run Python from the command line. Especially for testing purposes. The only drawback is that after making a change in the script, I have to restart Python, do all the imports over again, create the objects and enter the parameters.

$ python
>>> from foo import bar
>>> from package.file import Class
>>> c = Class
>>> c.name = "John"
>>> c.age = 33
>>> c.function()
>>> from datetime import timedelta, datetime
>>> now = datetime.now().year()
>>> next_year = now + timedelta(year=1)
>>> etc...

Can someone tell me if there is an easier way then doing all the work over and over again every time I make a change in the Python code?

It would help if you were clearer about what you're trying to do after changing the script. Are you testing functionality? — Harry Harrison, Nov 15 '15 at 17:35
Possible duplicate of [How do I watch a file for changes using Python?](http://stackoverflow.com/questions/182197/how-do-i-watch-a-file-for-changes-using-python) — Papouche Guinslyzinho, Nov 15 '15 at 17:40

score 1 · Answer 1 · answered Nov 15 '15 at 17:16

1

Use IPython with a notebook instead. Much better for interactive computing.

answered Nov 15 '15 at 17:16

Adam Acosta

603
3
6

score 1 · Accepted Answer · edited May 23 '17 at 12:15

You could consider turning your testing into an actual python script. which can be run like this, and then checking the output

$ python my_tests.py

However, a much better way would be to write some unit tests which you can run in a similar way. https://docs.python.org/2/library/unittest.html. The unittest framework will run all the tests you've defined and gather the results into a report.

If you need some steps to be done interactively, then you can achieve that by writing your setup into a script, and then executing the script before doing your interactive tests. See this other SO question: Is there a possibility to execute a Python script while being in interactive mode

score 0 · Answer 3 · answered Nov 15 '15 at 18:42

Going for IPython as well. You can write a script which will enter an interactive shell at any point in any frame, for example:

import IPython
from foo import bar
from package.file import Class
c = Class
c.name = "John"
c.age = 33
c.function()
from datetime import timedelta, datetime
now = datetime.now().year()
next_year = now + timedelta(year=1)
IPython.embed()

Then simply run your script with python, and you'll get an interactive shell at the end.

Rerun python program from terminal after making changes

3 Answers3