The except statement with no exception
Python provides the flexibility not to specify the name of the exception with the exception statement.
Consider the following example.
try:
a = int(input("Enter a:"))
b = int(input("Enter b:"))
c = a/b;
print("a/b = %d"%c)
#print("a/b = ",c)
print("{}/{} = {}".format(a,b,c))
except:
print("can't divide by zero")
else:
print("Hi I am else block")
Output:
Case 1:
Enter a:10
Enter b:6
a/b = 1
10/6 = 1.6666666666666667
Hi I am else block
Case 2:
Enter a:25
Enter b:0
can’t divide by zero
The except statement using with exception variable
We can use the exception variable with the except statement. It is used by using the as keyword. this object will return the cause of the exception.
Consider the following example:
try:
a = int(input("Enter a:"))
b = int(input("Enter b:"))
c = a/b
print("a/b = %d"%c)
# Using exception object with the except statement
except Exception as e:
print("can't divide by zero")
#to display system defined message
print(e)
else:
print("Hi I am else block")
Output:
Case:1
Enter a:10
Enter b:6
a/b = 1
Hi I am else block
Case:2
Enter a:10
Enter b:0
can’t divide by zero
division by zero
Example:
try:
#this will throw an exception if the file doesn't exist.
fileptr = open("file.txt","r")
except IOError:
print("File not found")
else:
print("The file opened successfully")
temp=fileptr.read()
print(temp)
fileptr.close()
Output:(if the file is present)
The file opened successfully
hello this is
file.txt file
Output:(if the file is not present)
File not found
Important points to remember
1. Python facilitates us to not specify the exception with the except statement.
2. We can declare multiple exceptions in the except statement since the try block may contain the statements which throw the different type of exceptions.
3. We can also specify an else block along with the try-except statement, which will be executed if no exception is raised in the try block.
4. The statements that don’t throw the exception should be placed inside the else block.
