Running test cases in parallel

Key 5: Faster test suite execution

When we have accumulated a lot of test cases in the project, it takes a lot of time to execute all of the test cases. We have to make the test run in parallel to decrease the time that is taken overall. In this case, the py.test testing framework does a fantastic job of simplifying the ability to run tests in parallel. To make this work, we have to first install the py.test library, and then use its runner to run the test cases. The py.test library has an xdist plugin, which adds the capability to run tests in parallel, as follows:

(py35) [ ch6 ] $ py.test -n 3 test_system.py
========================================== test session starts ===========================================
platform linux -- Python 3.5.0, pytest-2.8.2, py-1.4.30, pluggy-0.3.1
rootdir: /home/arun/codes/workspace/pybook/ch6, inifile: 
plugins: xdist-1.13.1
gw0 [5] / gw1 [5] / gw2 [5]
scheduling tests via LoadScheduling
s...F
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