try:
  You do your operations here;
  ......................
except ExceptionI:
  If there is ExceptionI, then execute this block.
except ExceptionII:
  If there is ExceptionII, then execute this block.
  ......................
else:
  If there is no exception then execute this block. 

#!/usr/bin/python

try:
  fh = open("testfile", "w")
  fh.write("This is my test file for exception handling!!")
except IOError:
  print "Error: can\'t find file or read data"
else:
  print "Written content in the file successfully"
  fh.close()

Written content in the file successfully

#!/usr/bin/python

try:
  fh = open("testfile", "r")
  fh.write("This is my test file for exception handling!!")
except IOError:
  print "Error: can\'t find file or read data"
else:
  print "Written content in the file successfully"

Error: can't find file or read data

try:
  You do your operations here;
  ......................
except:
  If there is any exception, then execute this block.
  ......................
else:
  If there is no exception then execute this block. 

try:
  You do your operations here;
  ......................
except(Exception1[, Exception2[,...ExceptionN]]]):
  If there is any exception from the given exception list, 
  then execute this block.
  ......................
else:
  If there is no exception then execute this block. 

try:
  You do your operations here;
  ......................
  Due to any exception, this may be skipped.
finally:
  This would always be executed.
  ......................

#!/usr/bin/python

try:
  fh = open("testfile", "w")
  fh.write("This is my test file for exception handling!!")
finally:
  print "Error: can\'t find file or read data"

Error: can't find file or read data

#!/usr/bin/python

try:
  fh = open("testfile", "w")
  try:
   fh.write("This is my test file for exception handling!!")
  finally:
   print "Going to close the file"
   fh.close()
except IOError:
  print "Error: can\'t find file or read data"

try:
  You do your operations here;
  ......................
except ExceptionType, Argument:
  You can print value of Argument here...

#!/usr/bin/python

# Define a function here.
def temp_convert(var):
  try:
   return int(var)
  except ValueError, Argument:
   print "The argument does not contain numbers\n", Argument

# Call above function here.
temp_convert("xyz");

The argument does not contain numbers
invalid literal for int() with base 10: 'xyz'

raise [Exception [, args [, traceback]]]

def functionName( level ):
  if level < 1:
   raise "Invalid level!", level
   # The code below to this would not be executed
   # if we raise the exception

try:
  Business Logic here...
except "Invalid level!":
  Exception handling here...
else:
  Rest of the code here...

class Networkerror(RuntimeError):
  def __init__(self, arg):
   self.args = arg

try:
  raise Networkerror("Bad hostname")
except Networkerror,e:
  print e.args