title: Name error with regular expression
body: <p>I am trying to parse the a file content with regular expression as in the code below. If I print the system name inside 'IF' suite, it works. But If I try to do anywhere outside, its throwing name error. Any help would be really appreciated.</p>
  
  <pre><code>#!/usr/bin/python
  import re
  f=open("cdp-nei1.txt")
  f=f.readlines()
  
  for data in f:
      cdp_line = data.split("\n")
      for line in cdp_line:
          if "System Name" in line:
              systemname = re.search(r"System Name:(.+)",line)
              systemname =  systemname.group(1)
              print systemname
  </code></pre>
  
  <hr>
  
  <p>./show-cdp.py </p>
  
  <p>Router1</p>
  
  <hr>
  
  <pre><code>#!/usr/bin/python
  import re
  f=open("cdp-nei1.txt")
  f=f.readlines()
  
  for data in f:
      cdp_line = data.split("\n")
      for line in cdp_line:
          if "System Name" in line:
              systemname = re.search(r"System Name:(.+)",line)
              systemname =  systemname.group(1)
          print systemname
  
  ***
  
   ./show-cdp.py 
  
  Traceback (most recent call last):
    File "./show-cdp.py", line 12, in &lt;module&gt;
      print systemname
  NameError: name 'systemname' is not defined
  </code></pre>
  
  <hr>
  
  <p>File Content  (Truncated to show only one block)</p>
  
  <hr>
  
  <pre><code>Device ID:Router1
  System Name: Router1
  
  Interface address(es):
      IPv4 Address: 10.0.0.1
  Platform: N5K-C5672UP, Capabilities: Router Switch IGMP Filtering Supports-STP-Dispute
  Interface: mgmt0, Port ID (outgoing port): Ethernet101/1/47
  Holdtime: 179 sec
  
  Version:
  Cisco Nexus Operating System (NX-OS) Software, Version 7.0(1)N1(1)
  
  Advertisement Version: 2
  
  Native VLAN: 1
  Duplex: full
  
  MTU: 1500
  Physical Location: Somewhere,United States
  Mgmt address(es):
      IPv4 Address: 10.0.0.1
  </code></pre>