Python except Keyword

Note: We can define multiple blocks with except keyword to handle the different types of expectations by mentioning the error/exception names.

Syntax

Syntax of except keyword:

try:
  statement(s)-1
except:
  statement(s)-2

While executing the statement(s)-1, if there is any exception raises, control jumps to except block and statement(s)-2 executes.

Syntax

Syntax of except keyword with multiple except blocks:

try:
  statement(s)-1
except Error_Name1:
  statement(s)-A
except Error_Name2:
  statement(s)-B
except Error_Name3:
  statement(s)-C
..
except:
  statement(s)-default

While executing the statement(s)-1 if Error_Name1 generates, statements written in Except Error_Name1 (statements(s)-A) executes, and so on... If any error is not mentioned with except block then last except block without any error name executes.

Sample Input/Output

  Input:
  a = 10
  b = 0

  try:
    # no error
    result = a%b
    print(result)
  
  except:
    print("There is an error")

  Output:
  There is an error

Example 1

Find modulus of two number and handle exception, if divisor is 0.

# python code to demonstrate example of 
# except keyword 

# Find modulus of two number and 
# handle exception, if divisor is 0

a = 10
b = 3

try:
  # no error
  result = a%b
  print(result)
  
  # assign 0 to b
  # an error will occur
  b = 0
  result = a%b
  print(result)
  
except:
  print("There is an error")

Output

1
There is an error

Example 2

Write an example to handle multiple errors.

# python code to demonstrate example of 
# except keyword 

# Write an example to handle multiple errors

a = 10
b = 3

try:
  # del b # uncomment this to test NameError
  # no error
  result = a%b
  print(result)
  
  # assign 0 to b
  # an error will occur
  b = 0
  result = a%b
  print(result)
  
except ZeroDivisionError:
  print("Can not divide by 0")
except NameError:
  print("A NameError in the code")
except:
  print("There is an error")

Output

1
Can not divide by 0