Running unittest with typical test directory structure

Question

The very common directory structure for even a simple Python module seems to be to separate the unit tests into their own test directory   new project      antigravity          antigravity py     test          test antigravity py     setup py     etc    for example see this Python project howto   My question is simply What s the usual way of actually running the tests  I suspect this is obvious to everyone except me  but you can t just run python test antigravity py from the test directory as its import antigravity will fail as the module is not on the path   I know I could modify PYTHONPATH and other search path related tricks  but I can t believe that s the simplest way - it s fine if you re the developer but not realistic to expect your users to use if they just want to check the tests are passing   The other alternative is just to copy the test file into the other directory  but it seems a bit dumb and misses the point of having them in a separate directory to start with   So  if you had just downloaded the source to my new project how would you run the unit tests  I d prefer an answer that would let me say to my users   To run the unit tests do X

User · Answer

This BASH script will execute the python unittest test directory from anywhere in the file system, no matter what working directory you are in.

This is useful when staying in the ./src or ./example working directory and you need a quick unit test:

#!/bin/bash

this_program="$0"
dirname="`dirname $this_program`"
readlink="`readlink -e $dirname`"

python -m unittest discover -s "$readlink"/test -v

No need for a test/__init__.py file to burden your package/memory-overhead during production.

User · Answer

You can t import from the parent directory without some voodoo  Here s yet another way that works with at least Python 3 6   First  have a file test context py with the following content   import sys import os sys path insert 0  os path abspath os path join os path dirname   file               Then have the following import in the file test test antigravity py   import unittest try      import context except ModuleNotFoundError      import test context     import antigravity   Note that the reason for this try-except clause is that    import test context fails when run with  python test antigravity py  and  import context fails when run with  python -m unittest  from the new project directory    With this trickery they both work    Now you can run all the test files within test directory with     pwd  projects new project   python -m unittest   or run an individual test file with     cd test   python test antigravity   Ok  it s not much prettier than having the content of context py within test antigravity py  but maybe a little  Suggestions are welcome

User · Answer

Solution Example for Python unittest module  Given the following project structure   ProjectName   -- project name        -- models             -- thing 1 py        --   main   py   -- test        -- models             -- test thing 1 py        --   main   py   You can run your project from the root directory with python project name  which calls ProjectName project name   main   py     To run your tests with python test  effectively running ProjectName test   main   py  you need to do the following   1  Turn your test models directory into a package by adding a   init   py file  This makes the test cases within the sub directory accessible from the parent test directory     ProjectName test models   init   py  from  test thing 1 import Thing1TestCase           2  Modify your system path in test   main   py to include the project name directory     ProjectName test   main   py  import sys import unittest  sys path append     project name    loader   unittest TestLoader   testSuite   loader discover  test   testRunner   unittest TextTestRunner verbosity 2  testRunner run testSuite      Now you can successfully import things from project name in your tests     ProjectName test models test thing 1 py      import unittest from project name models import Thing1    this doesn t work without  sys path append  per step 2 above  class Thing1TestCase unittest TestCase        def test thing 1 init self           thing id    ABC          thing1   Thing1 thing id          self assertEqual thing id  thing id

User · Answer

I had the same problem  with a separate unit tests folder  From the mentioned suggestions I add the absolute source path to sys path   The benefit of the following solution is  that one can run the file test test yourmodule py without changing at first into the test-directory   import sys  os testdir   os path dirname   file    srcdir       antigravity  sys path insert 0  os path abspath os path join testdir  srcdir     import antigravity import unittest

User · Answer

Python 3   Adding to  Pierre  Using unittest directory structure like this   new project  -- antigravity         --   init   py           make it a package         -- antigravity py  -- test      --   init   py           also make test a package      -- test antigravity py   To run the test module test antigravity py     cd new project   python -m unittest test test antigravity   Or a single TestCase     python -m unittest test test antigravity GravityTestCase   Mandatory don t forget the   init   py even if empty otherwise will not work

User · Answer

If you use VS Code and your tests are located on the same level as your project then running and debug your code doesn t work out of the box  What you can do is change your launch json file          version    0 2 0        configurations                            name    Python                type    python                request    launch                stopOnEntry   false               pythonPath      config python pythonPath                 program      file                 cwd      workspaceRoot                 env                    envFile      workspaceRoot   env                debugOptions                      WaitOnAbnormalExit                    WaitOnNormalExit                    RedirectOutput                                        The key line here is envFile   envFile      workspaceRoot   env     In the root of your project add  env file  Inside of your  env file add path to the root of your project  This will temporarily add      PYTHONPATH C  YOUR PYTHON PROJECT ROOT DIRECTORY   path to your project and you will be able to use debug unit tests from VS Code

User · Answer

I noticed that if you run the unittest command line interface from your  src  directory  then imports work correctly without modification   python -m unittest discover -s    test   If you want to put that in a batch file in your project directory  you can do this   setlocal  amp  cd src  amp  python -m unittest discover -s    test

User · Answer

Following is my project structure   ProjectFolder   - project       -   init   py      - item py  - tests       - test item py   I found it better to import in the setUp   method   import unittest import sys      class ItemTest unittest TestCase        def setUp self           sys path insert 0      project           from project import item           further setup using this import      def test item props self             do my assertions  if   name         main         unittest main

User · Answer

Use setup py develop to make your working directory be part of the installed Python environment  then run the tests

User · Answer

It s possible to use wrapper which runs selected or all tests   For instance     run tests antigravity   py   or to run all tests recursively use globbing  tests      py   enable by shopt -s globstar    The wrapper can basically use argparse to parse the arguments like   parser   argparse ArgumentParser   parser add argument  files   nargs        Then load all the tests   for filename in args files      exec open filename  read      then add them into your test suite  using inspect    alltests   unittest TestSuite   for name  obj in inspect getmembers sys modules   name          if inspect isclass obj  and name startswith  FooTest            alltests addTest unittest makeSuite obj     and run them   result   unittest TextTestRunner verbosity 2  run alltests    Check this example for more details   See also  How to run all Python unit tests in a directory

User · Answer

The simplest solution for your users is to provide an executable script  runtests py or some such  which bootstraps the necessary test environment  including  if needed  adding your root project directory to sys path temporarily  This doesn t require users to set environment variables  something like this works fine in a bootstrap script   import sys  os  sys path insert 0  os path dirname   file       Then your instructions to your users can be as simple as  python runtests py    Of course  if the path you need really is os path dirname   file     then you don t need to add it to sys path at all  Python always puts the directory of the currently running script at the beginning of sys path  so depending on your directory structure  just locating your runtests py at the right place might be all that s needed   Also  the unittest module in Python 2 7   which is backported as unittest2 for Python 2 6 and earlier  now has test discovery built-in  so nose is no longer necessary if you want automated test discovery  your user instructions can be as simple as python -m unittest discover

User · Answer

If you are looking for a command line-only solution   Based on the following directory structure  generalized with a dedicated source directory    new project      src          antigravity py     test          test antigravity py   Windows   in new project     set PYTHONPATH  PYTHONPATH   cd  src   python -m unittest discover -s test   See this question if you want to use this in a batch for-loop   Linux   in new project     export PYTHONPATH  PYTHONPATH   pwd  src   I think - please edit this answer if you are a Linux user and you know this    python -m unittest discover -s test   With this approach  it is also possible to add more directories to the PYTHONPATH if necessary

User · Answer

What s the usual way of actually running the tests   I use Python 3 6 2  cd new project  pytest test test antigravity py   To install pytest  sudo pip install pytest  I didn t set any path variable and my imports are not failing with the same  test  project structure   I commented out this stuff  if   name         main    like this   test antigravity py  import antigravity  class TestAntigravity unittest TestCase        def test something self                  test stuff here     if   name         main              if   package   is None               import something           sys path append path dirname path dirname path abspath   file                 from    import antigravity          else               from    import antigravity          unittest main

User · Answer

You should really use the pip tool   Use pip install -e   to install your package in development mode  This is a very good practice  recommended by pytest  see their good practices documentation  where you can also find two project layouts to follow

User · Answer

The best solution in my opinion is to use the unittest command line interface which will add the directory to the sys path so you don t have to  done in the TestLoader class    For example for a directory structure like this   new project  -- antigravity py  -- test antigravity py   You can just run     cd new project   python -m unittest test antigravity   For a directory structure like yours   new project  -- antigravity         --   init   py           make it a package         -- antigravity py  -- test      --   init   py           also make test a package      -- test antigravity py   And in the test modules inside the test package  you can import the antigravity package and its modules as usual     import the package import antigravity    import the antigravity module from antigravity import antigravity    or an object inside the antigravity module from antigravity antigravity import my object   Running a single test module   To run a single test module  in this case test antigravity py     cd new project   python -m unittest test test antigravity   Just reference the test module the same way you import it   Running a single test case or test method   Also you can run a single TestCase or a single test method     python -m unittest test test antigravity GravityTestCase   python -m unittest test test antigravity GravityTestCase test method   Running all tests   You can also use test discovery which will discover and run all the tests for you  they must be modules or packages named test  py  can be changed with the -p  --pattern flag      cd new project   python -m unittest discover     Also works without discover for Python 3     as suggested by  Burrito in the comments   python -m unittest   This will run all the test  py modules inside the test package

User · Answer

A simple solution for  nix based systems  macOS  Linux   and probably also Git bash on Windows  PYTHONPATH  PWD python test test antigravity py  print statement easily works  unlike pytest test test antigravity py  A perfect way for  quot scripts quot   but not really for unittesting  Of course  I want to do a proper automated testing  I would consider pytest with appropriate settings

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I generally create a  run tests  script in the project directory  the one that is common to both the source directory and test  that loads my  All Tests  suite  This is usually boilerplate code  so I can reuse it from project to project   run tests py   import unittest import test all tests testSuite   test all tests create test suite   text runner   unittest TextTestRunner   run testSuite    test all tests py  from How do I run all Python unit tests in a directory    import glob import unittest  def create test suite        test file strings   glob glob  test test   py       module strings     test   str 5 len str -3  for str in test file strings      suites    unittest defaultTestLoader loadTestsFromName name                  for name in module strings      testSuite   unittest TestSuite suites      return testSuite   With this setup  you can indeed just include antigravity in your test modules  The downside is you would need more support code to execute a particular test    I just run them all every time

User · Answer

From the article you linked to      Create a test modulename py file and   put your unittest tests in it  Since   the test modules are in a separate   directory from your code  you may need   to add your module   s parent directory   to your PYTHONPATH in order to run   them     cd  path to googlemaps    export PYTHONPATH  PYTHONPATH  path to googlemaps googlemaps    python test test googlemaps py       Finally  there is one more popular   unit testing framework for Python    it   s that important    nose  nose   helps simplify and extend the builtin   unittest framework  it can  for   example  automagically find your test   code and setup your PYTHONPATH for   you   but it is not included with the   standard Python distribution    Perhaps you should look at nose as it suggests

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I ve had the same problem for a long time  What I recently chose is the following directory structure   project path  -- Makefile  -- src       -- script 1 py       -- script 2 py       -- script 3 py  -- tests      --   init   py      -- test script 1 py      -- test script 2 py      -- test script 3 py   and in the   init   py script of the test folder  I write the following   import os import sys PROJECT PATH   os getcwd   SOURCE PATH   os path join      PROJECT PATH  src    sys path append SOURCE PATH    Super important for sharing the project is the Makefile  because it enforces running the scripts properly  Here is the command that I put in the Makefile   run tests      python -m unittest discover     The Makefile is important not just because of the command it runs but also because of where it runs it from  If you would cd in tests and do python -m unittest discover    it wouldn t work because the init script in unit tests calls os getcwd    which would then point to the incorrect absolute path  that would be appended to sys path and you would be missing your source folder   The scripts would run since discover finds all the tests  but they wouldn t run properly  So the Makefile is there to avoid having to remember this issue   I really like this approach because I don t have to touch my src folder  my unit tests or my environment variables and everything runs smoothly    Let me know if you guys like it    Hope that helps

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This way will let you run the test scripts from wherever you want without messing around with system variables from the command line   This adds the main project folder to the python path  with the location found relative to the script itself  not relative to the current working directory    import sys  os  sys path insert 0  os path dirname os path dirname os path realpath   file         Add that to the top of all your test scripts  That will add the main project folder to the system path  so any module imports that work from there will now work  And it doesn t matter where you run the tests from    You can obviously change the project path hack file to match your main project folder location

User · Answer

if you run  python setup py develop  then the package will be in the path  But you may not want to do that because you could infect your system python installation  which is why tools like virtualenv and buildout exist

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If you have multiple directories in your test directory  then you have to add to each directory an   init   py file    home johndoe snakeoil  -- test      --   init   py              -- frontend          --   init   py          -- test foo py      -- backend          --   init   py          -- test bar py   Then to run every test at once  run   python -m unittest discover -s  home johndoe snakeoil test -t  home johndoe snakeoil   Source   python -m unittest -h    -s START  --start-directory START                         Directory to start discovery      default    -t TOP  --top-level-directory TOP                         Top level directory of project  defaults to start                         directory

[python] Running unittest with typical test directory structure

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