I'm using pytest for my test suite. While catching bugs in complex inter-components test, I would like to place import ipdb; ipdb.set_trace() in the middle of my code to allow me to debug it.
However, since pytest traps sys.stdin/sys.stdout ipdb fails. How can I use ipdb while testing with pytest.
I'm not interested in jumping to pdb or ipdb after a failure, but to place breaks anywhere in the code and be able to debug it there before the failure occurs.
The error is raised because pytest captures output by default.
You can run pytest with -s option (turn off capture output). For example:
py.test -s my_test.py
and then in my_test.py:
import ipdb;
ipdb.set_trace()
pytest-ipdb is unfortunately not supported anymore.
The solution is to run
pytest my_test.py --pdb --pdbcls=IPython.terminal.debugger:Pdb
From the help command:
pytest -h
--pdb start the interactive Python debugger on errors.
--pdbcls=modulename:classname
start a custom interactive Python debugger on errors.
For example:
--pdbcls=IPython.terminal.debugger:TerminalPdb
The difference is just that TerminalPdb seems to throw erros, but Pdb not (Ipython docs).
As of 2019-11 here is what should fix it:
pip install ipdb gnureadline ptpython
export PYTEST_ADDOPTS='--pdb --pdbcls=IPython.terminal.debugger:Pdb'
This is what I use
py.test tests/ --pdbcls=IPython.core.debugger:Pdb -s
You may want to give pdbpp a try. I've had more success with it, compared to ipdb when used with pytest. See my answer here: https://stackoverflow.com/a/69320311/2896799.
Related
I have problem in importing pytest while writing a python code. "import pytest is grayed out.
Python is 3.8.3, Pycharm community edition.
pytest version 5.4.2, is successfully installed and can be seen in the project interpreter in pycharm. As well as I can see the installed path of pytest in python directory.
When running py.test command from console. It starts the test run shows "collected 0 items" and lastly ends with "NO TESTS RAN IN 0.05s"
If anyone running similar problems with some other packages kindly let me know.
TIA...
You simply run pytest from the commandline. There is no need to import pytest into a script. Take this Python script as an example:
def inc(x):
return x + 1
def test_answer():
assert inc(3) == 4
To run pytest on it, from the terminal (after changing to the right directory):
$ pytest
And you will then see the test outcome in the commandline as pytest automatically picks up the python scripts names test_*.py, where * is any name, e.g. test_increment.py. To have a test from your Python script run, name it with test_ as well to begin with.
Running pytest in the terminal is an option. In addition, Pycharm has integrated test suite for automatic discovery and collection of test tasks. You can use hotkey ctrl+shift+10 to run the test tasks directly in current file .
This is the structure of my project, and I would like to run the test that I have made from the command line.
I am using the following command:
python test_hotel.py
However I am getting the following error
ImportError: No module named 'hotel'
What can I do to solve this problem, and is there a way to execute the whole tests in a project from the command line.
Thanks in advance.
For running unittest from commandline, you should use this command:
python -m unittest tests.test_hotel
You need to make sure that you have followed the rules in writing unittests (https://docs.python.org/2/library/unittest.html)
As #shahram kalantari said to run a tests the command line is:
python -m unittest tests.test_hotel
If one wants to run the whole tests the command line is:
python -m unittest discover tests
If you want more information about what tests were run the -v flag should be included:
python -m unittest discover tests -v
I am having some trouble trying to debug some unit tests through the pudb debugger.
The tests run fine with python, but I had no luck runnign them with pudb.
I isolated the problem, getting to the following sample code:
class Math:
def pow(self, x, y):
return x ** y
import unittest
class MathTest(unittest.TestCase):
def testPow23(self):
self.assertEquals(8, Math().pow(2, 3))
def testPow24(self):
self.assertEquals(16, Math().pow(2, 4))
if __name__ == '__main__':
unittest.main()
The tests run fine:
$ python amodule.py
.
----------------------------------------------------------------------
Ran 2 tests in 0.001s
OK
But if running through pudb, it gives me the output:
----------------------------------------------------------------------
Ran 0 tests in 0.000s
OK
I've tried running using pudb amodule.py and also with python -m pudb.run amodule.py, but it makes no difference -- no tests are run in one or another way.
Should I be doing something different to debug unit tests using pudb?
Try placing a breakpoint on a useful line in your code:
from pudb import set_trace; set_trace()
The ways you tried to launch it might interfere with test discovery and/or not run your script with a __name__ of '__main__'.
Since this is a popular question, I feel I should also mention that most test running tools will require you to pass in a switch to prevent it from capturing the standard output and input (usually it's -s).
So, remember to run pytest -s when using Pytest, or nosetests -s for Nose, python manage.py test -s for Django tests, or check the documentation for your test running tool.
You can set a breakpoint even easier by:
import pudb; pu.db
I would like to use the built in Pytest runner of PyCharm together with the debugger without pre-configuring breakpoints.
The problem is that exceptions in my test are caught by Pytest so PyCharm's post mortem debugger cannot handle the exception.
I know using a breakpoint works but I would prefer not to run my test twice.
Found a way to do this in Unittest, I would like to know if something like this exists in Pytest.
Is there a way to catch unittest exceptions with PyCharm?
Are you using pytest-pycharm plugin? Looks like it works for me. Create virtualenv, pip install pytest pytest-pycharm, use this virtualenv at PyCharm Edit configuration -> Python Interpreter and then run with Debug ... Example:
import pytest
def test_me():
assert None
if __name__ == '__main__':
pytest.main(args=[__file__])
PyCharm debugger stops at assert None point, with (<class '_pytest.assertion.reinterpret.AssertionError'>, AssertionError(u'assert None',), None)
EDIT
Set Preferences > Tools > Python Integration Tools > Default test runner to py.test. Then Run > Debug 'py.test in test_me.py'
I'm trying to suppress all sqlalchemy warnings while running my test suite with nosetests. I read Turn off a warning in sqlalchemy
.............................../Users/ca/.pythonbrew/venvs/Python-2.7.3/api/lib/python2.7/site-packages/SQLAlchemy-0.7.5-py2.7-macosx-10.7-x86_64.egg/sqlalchemy/engine/default.py:330: Warning: Field 'random_id' doesn't have a default value
cursor.execute(statement, parameters)
I included this in my package's __init__.py file:
def setup_package():
"""Setup the test during the whole session.
Run by nosetests
"""
# Suppress all SQLAlchemy warnings
warnings.filterwarnings("ignore", category=sa_exc.SAWarning)
With the proper imports. I know it is run by nosetests because I tried some other stuff which raised error. The only thing is that it has no effect whatsoever. Warnings are still displayed.
Any idea?
Thanks!
It seems that nose overwrites whatever you set with:
warnings.filterwarnings("ignore")
However you can filter warnings during nose test with a command line option to nose. e.g.:
$ nosetests --logging-filter=SAWarning
I found that this still may not work under all circumstances. If this is the case you can try:
$ python -W ignore `which nosetests`