title: pyvisa-py on raspberry pi AttributeError: 'module' object has no attribute 'ResourceManager'
body: <p>py on a raspberry pi with python 2.7.9 and pip 1.5.6. I installed and uninstalled pyvisa and pyvisa-py several times, but the problems stay. I connected the KEITHLEY Multimeter 2000 per R232 to USB with the Raspberry.</p>
  
  <p>When I run the basic Code:
  <code>
  import visa
  rm = visa.ResourceManager('@py')
  a=rm.list_resources()
  print(a)
  </code>
  I receive:
  <code>
  Traceback (most recent call last):
    File "pyvisa.py", line 1, in &lt;module&gt;
      import visa
    File "/usr/local/lib/python2.7/dist-packages/visa.py", line 16, in &lt;module&gt;
      from pyvisa import logger, __version__, log_to_screen, constants
    File "/home/pi/pyvisa.py", line 2, in &lt;module&gt;
      rm = visa.ResourceManager('@py')
  AttributeError: 'module' object has no attribute 'ResourceManager'
  </code></p>
  
  <p>as well when I try</p>
  
  <p><code>python -m visa info</code></p>
  
  <p><code>
  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/visa.py", line 16, in &lt;module&gt;
      from pyvisa import logger, __version__, log_to_screen, constants
    File "pyvisa.py", line 1, in &lt;module&gt;
      import visa
    File "/usr/local/lib/python2.7/dist-packages/visa.py", line 16, in &lt;module&gt;
      from pyvisa import logger, __version__, log_to_screen, constants
  ImportError: cannot import name logger
  </code>
  On the other hand i can't upgrade, because the requirements are already up-to-date.
  <code>
  pip install pyvisa-py --upgrade
  Requirement already up-to-date: pyvisa-py in /usr/local/lib/python2.7/dist-packages
  Requirement already up-to-date: pyvisa&gt;=1.8 in /usr/local/lib/python2.7/dist-packages (from pyvisa-py)
  Requirement already up-to-date: enum34 in /usr/local/lib/python2.7/dist-packages (from pyvisa&gt;=1.8-&gt;pyvisa-py)
  </code>
  I would be very thankfull if somebody could help me with this issue.</p>