This link gives a description how to use pytest for capturing console outputs. I tried on this following simple code, but I get error
import sys
import pytest
def f(name):
print "hello "+ name
def test_add(capsys):
f("Tom")
out,err=capsys.readouterr()
assert out=="hello Tom"
test_add(sys.stdout)
Output:
python test_pytest.py
hello Tom
Traceback (most recent call last):
File "test_pytest.py", line 12, in <module>
test_add(sys.stdout)
File "test_pytest.py", line 8, in test_add
out,err=capsys.readouterr()
AttributeError: 'file' object has no attribute 'readouterr'
what is wrong and what fix needed? thank you
EDIT:
As per the comment, I changed capfd
, but I still get the same error
import sys
import pytest
def f(name):
print "hello "+ name
def test_add(capfd):
f("Tom")
out,err=capfd.readouterr()
assert out=="hello Tom"
test_add(sys.stdout)
Use the capfd
fixture.
Example:
def test_foo(capfd):
foo() # Writes "Hello World!" to stdout
out, err = capfd.readouterr()
assert out == "Hello World!"
See: http://pytest.org/en/latest/fixture.html for more details
And see: py.test --fixtures
for a list of builtin fixtures.
Your example has a few problems. Here is a corrected version:
def f(name):
print "hello {}".format(name)
def test_f(capfd):
f("Tom")
out, err = capfd.readouterr()
assert out == "hello Tom\n"
Note:
sys.stdout
-- Use the capfd
fixture as-is as provided by pytest.py.test foo.py
Test Run Output:
$ py.test foo.py
====================================================================== test session starts ======================================================================
platform linux2 -- Python 2.7.5 -- pytest-2.4.2
plugins: flakes, cache, pep8, cov
collected 1 items
foo.py .
=================================================================== 1 passed in 0.01 seconds ====================================================================
Also Note:
py.test
(The CLI tool and Test Runner) does this for you.py.test does mainly three things:
By default py.test
looks for (configurable iirc) test_foo.py
test modules and test_foo()
test functions in your test modules.