title: Unable to get full VISA address that includes the serial number
body: <p>I do not have any prior experience in Python and was trying to see if I can query information from a device with USB VISA address. I am running a Raspbian GNU/Linux 9 (stretch) with a Python 3.5.3 Shell. The VISA packages for python was installed using pip3:</p>
  
  <pre><code>$ sudo pip3 install pyvisa-py
  </code></pre>
  
  <p>Since I am interfacing the device with USB interface, I installed the python USB package as well.</p>
  
  <pre><code>$ sudo pip3 install pyusb
  </code></pre>
  
  <p>When I use the generic commands as per <a href="https://pyvisa.readthedocs.io/en/stable/getting.html" rel="nofollow noreferrer">PyVISA website</a>, I am able to read the partial VISA address without the serial number as shown below:</p>
  
  <pre><code>&gt;&gt;&gt; import visa
  &gt;&gt;&gt; rm = visa.ResourceManager()
  &gt;&gt;&gt; print(rm.list_resources())
  Found a device whose serial number cannot be read. The partial VISA resource name is: USB0::2391::11032::???::0::INSTR
  ('ASRL/dev/ttyAMA0::INSTR',)
  </code></pre>
  
  <p>Here is the python VISA info:</p>
  
  <pre><code>$ python3 -m visa info 
  Machine Details:    
      Platform ID:    Linux-4.14.62-v7+-armv7l-with-debian-9.4    
      Processor:      
  
  Python:    
      Implementation: CPython    
      Executable:     /usr/bin/python3  
      Version:        3.5.3    
      Compiler:       GCC 6.3.0 20170124    
      Bits:           32bit    
      Build:          Jan 19 2017 14:11:04 (#default)    
      Unicode:        UCS4
  
  PyVISA Version: 1.9.1
  
  Backends:    
      ni:
        Version: 1.9.1 (bundled with PyVISA)
        Binary library: Not found    
      py:
        Version: 0.3.0
        TCPIP SOCKET: Available
        GPIB INSTR:
           Please install linux-gpib to use this resource type.
           No module named 'gpib'
        USB INSTR: Available via PyUSB (1.0.2). Backend: libusb1
        ASRL INSTR: Available via PySerial (3.2.1)
        USB RAW: Available via PyUSB (1.0.2). Backend: libusb1
        TCPIP INSTR: Available
  </code></pre>
  
  <p>Not sure what I am doing wrong. How do I read the full VISA resource name? Without that, even if I try to force open the device with the full VISA address, it would throw another error.</p>