Python Errors & Exception

A syntax error is an error in the python program.

>>> while True print 'Hello world' 

it is an Invalid Syntax error in the above code. It should be as :

>>> while True:
             print 'Hello world'

Standard Errors available in Python are:

Errors detected during execution are called exceptions. Even if a statement or expression is syntactically correct, it may cause an error when an attempt is made to execute it.

>> 10 * (1/10)

The above code is syntactically right, but when we execute it, but it will produce ZeroDivisionError: integer division or modulo by zero.

Standard Exceptions available in Python are:

FloatingPointError, ZeroDivisonError, EOFError, SystemExit, OverflowError, KeyboardInterrupt, IndexError, IOError

If we see some doubtful code that may produce an exception, we can secure our program by placing the code inside the try-except block.

try:
   you do your operation here
except Exception1:
   if there is Exception1, then execute this block
except Exception2:
   if there is Exception2, then execute this block 
.........
else:
   if there is no exception error, then execute this block of code. 

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")