Exception Handling 3

:

#If there is no exception

try:

   statement1

   statement2

   statement3

except:

   statement4

finally:

   statement5

statement6

output:

st1,2,3,5 and 6 executed

Case 2:

try:

   statement1

   statement2 #exception raised here

   statement3

except: #corresponding exception block is matched

   statement4

finally:

   statement5

statement6

output:

st1,4 ,,5 and 6 executed and Normal termination

Case 3:

try:

   statement1

   statement2 #exception raised here

   statement3

except: #corresponding exception block is not matched

   statement4

finally:

   statement5

statement6

output:

st1, 5 executed and Abnormal termination

#Case 4:Exception is raised in exception block

try:

   print("statement1 ")

   print("statement2 ")

   print("statement3")

except ZeroDivisionError:

   print(2/0)#exception raised here

finally:

   print("statement 5")

print("statement6")

"""output:

statement1

statement2

statement3

statement 5

statement6

#Case 5:Exception is raised in finally block

try:

   print("statement1 ")

   print("statement2 ")

   print("statement3")

except ZeroDivisionError:

   print("Statement 4")

finally:

   print(2/0)#exception raised here

print("statement6")

"""output:

statement1

statement2

statement3

Abnormal termination

"""

There is only two situation where finally block is not executed i.e when exception is raised in finally block, and os._exit(0) function.

Example:

#Case 5:finally is block is not executed when we use ox._exit(0)

import os

try:

   print("statement1 ")

   print("statement2 ")

   os._exit(0)

   print(2/0)

except ZeroDivisionError:

   print("Statement 4")

finally:

   print("Statement 5")

print("statement6")

"""output:

statement1

statement2

Nested try –except-finally blocks

"""

#Nested try blocks

try:

    print("outer try block")

    try:

        print("inner try block")

        print(2/0) #exception raises here, and corresponding except is matched

    except ZeroDivisionError:

        print("inner except block")

    finally:

        print("inner finally block")

except:

    print("outer except block")

finally:

    print("outer finally block")

"""output:

outer try block

inner try block

inner except block

inner finally block

outer finally block

>>>

"""

We can take try-except-finally blocks inside try or except or finally blocks it is called nesting exception handling.

Generally risky code we have to take inside outer try block and too much risky code we have to take inside inner try block.

·       Inside inner try block if an exception raised then except block is responsible to handle.  If it unable to handle then outer except block is responsible to handle.

Syntax:

try:

      ……

      ……

      try:

       ……..

       ………

       except:

       ……..

       ………

except:

      ……

      ……

Related Video: https://youtu.be/Rk9lzGZor34

Next: User Defined Exception
Previous:Exception Handling part 2

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