title: cant install pytest on macOs High sierra
body: <p>so now the installation is done, it doesnt detect that it is installed, it tells me pytest command no found
  Here is the command:</p>
  
  <pre><code>pytest --version
  </code></pre>
  
  <p>Here is the error:</p>
  
  <pre><code>Mostafas-MacBook-Pro:bin mostafa.osama2$ pip install --user -U pytest
  Collecting pytest
    Downloading pytest-3.3.1-py2.py3-none-any.whl (184kB)
      100% |████████████████████████████████| 194kB 4.0MB/s 
  Requirement already up-to-date: pluggy&lt;0.7,&gt;=0.5 in /Library/Python/2.7/site-packages (from pytest)
  Requirement already up-to-date: attrs&gt;=17.2.0 in /Library/Python/2.7/site-packages (from pytest)
  Requirement already up-to-date: py&gt;=1.5.0 in /Library/Python/2.7/site-packages (from pytest)
  Requirement already up-to-date: funcsigs; python_version &lt; "3.0" in /Library/Python/2.7/site-packages (from pytest)
  Collecting setuptools (from pytest)
    Downloading setuptools-38.2.4-py2.py3-none-any.whl (489kB)
      100% |████████████████████████████████| 491kB 2.4MB/s 
  Collecting six&gt;=1.10.0 (from pytest)
    Using cached six-1.11.0-py2.py3-none-any.whl
  Installing collected packages: setuptools, six, pytest
  Successfully installed pytest-3.3.1 setuptools-38.2.4 six-1.11.0
  Mostafas-MacBook-Pro:bin mostafa.osama2$ pytest --version
  -bash: pytest: command not found
  </code></pre>