Exception handling

         Programming is full of errors and exception. Errors are caused by the mistakes in the program. If you coded along while reading and experimented around a little bit.you may have encountered one or two error message

       They terminate our script and crash the program if they are not handled properly. There are 3 types of error

1) Syntax error

2) Runtime error

3) Logical error

->Syntax error can be rectified when compiler throws error

-> runtime error occurs during the program is running

->the program get executed but the output is not desired one

There are some more exception lets look into it:

IndentationError- raise when indentation is not specified properly

IndexError- raise when an index is not found in a sequence

NameError- raised when an identifier is not found in the local or global namespace

ZeroDivisionError- raised when division by zero takes place

KeyError- raised when specified key is not found in the dictionary

ValueError- raised when the built-in function for a data type has the valid type of arguments, but the argument have invalid value specified

Also there are some error which we will look in future post

Handling Exception:

The try and except statement are used to handle the runtime error.

Try: line of code that might encounter error

Except: line of code that will be executed when error occurs

try:
    print(10/0)
     text = "hello"
     number = int(text)
except ValueError:
    print(" valueError...")
except ZeroDivisionError:
   print("zero division error or code")
except:
  Print("other exception")

In the try block we put the code we want to execute. We calculate these are some errors going to occur so we put that error in except block. The except block tell our script what to do when respective error occurs. We provide code that handle the situation.we can also use else statement for multiple except block

try:
   print(10/0)
except:
   print("error")
except:
   print("zero division error")
else:
   print("everything ok")

In above block if there is error it shows error message else is shows everything ok

Finally statement:

These are the codes written inside a finally block which will be executed at last no matter what happens. These codes will also executed even if exception unhandled

Example:

try:
   print("hello")
   x=10/0
except ZeroDivisionError:
   print("zero division error")
finally:
   print("have a great day")

Output:

hello
zero division error
have a great day

Without except:

Hope you understand if not feel free to comment and share your thoughts also try your own programs!!!!