How to specify dependencies' version in `pip install` command?

Question

I specify installing pytest in Drone pipeline as below:

pip install -q pytest

it used to work well until a few days ago when it suddenly showed below error:

+ python -m pytest test/test_dai_adrecogzer.py
Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/usr/local/lib/python2.7/dist-packages/pytest.py", line 14, in <module>
    from _pytest.fixtures import fillfixtures as _fillfuncargs
  File "/usr/local/lib/python2.7/dist-packages/_pytest/fixtures.py", line 16, in <module>
    from more_itertools import flatten
  File "/usr/local/lib/python2.7/dist-packages/more_itertools/__init__.py", line 1, in <module>
    from more_itertools.more import *  # noqa
  File "/usr/local/lib/python2.7/dist-packages/more_itertools/more.py", line 329
    def _collate(*iterables, key=lambda a: a, reverse=False):
                               ^

SyntaxError: invalid syntax

Searching around I found a recently post SO question that seems to closely link to what I am looking for. The reason seems to be because of recently released version 6.0 of more-itertools. The accepted answer suggests to spin to some specific version of more-itertools:

setuptools.setup(
    setup_requires=['pytest-runner'],
    tests_require=['mock', 'more-itertools<6.0.0', 'pytest'],
    test_suite='tests',
    python_requires='>=2.7',
)

How could I apply this suggestion to my issue? More specifically, how could I specify version <6.0.0 of more-itertools when install pytest using pip install -q pytest command?

kederrac · Accepted Answer · 2019-02-13T09:38:41.307

1

you could specify a version of pytest that has an old version of more-itertools (for ex: pip install pytest==3.5.0)

I will not advise to install pytest with another version of more-iterators, other then one specified in setuptools because it may cause other crushes(pytest it may depend at some point on some features that your downgraded version doesn't have).

edited Feb 13 '19 at 09:38

answered Feb 13 '19 at 09:24

kederrac

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1

Oh yes, I go with `pip install -q pytest==3.4.2` and it works as expected. – duong_dajgja Feb 13 '19 at 09:45

score 1 · Answer 2 · answered Feb 13 '19 at 09:48

According to the pytest package specs on PyPI, the package requires more-itertools >=4.0.0. I would assume that, if you explicitly install any suitable version of more-itertools below 6.0.0 and above or equal 4.0.0, prior to running pip install -q pytest, the dependency check for more-itertools would already be satisfied and you could install the most recent version of pytest.

How to specify dependencies' version in `pip install` command?

2 Answers2