Try Statement

We can use try statements to handle exceptions. There are four clauses you can use (one more in addition to those shown in the video).

• try: This is the only mandatory clause in a try statement. The code in this block is the first thing that Python runs in a try statement.
• except: If Python runs into an exception while running the try block, it will jump to the except block that handles that exception.
• else: If Python runs into no exceptions while running the try block, it will run the code in this block after running the try block.
• finally: Before Python leaves this try statement, it will run the code in this finally block under any conditions, even if it's ending the program. E.g., if Python ran into an error while running code in the except or else block, this finally block will still be executed before stopping the program.

Why do we need the finally clause in Python?

Specifying Exceptions

We can actually specify which error we want to handle in an except block like this:

try:
    # some code
except ValueError:
    # some code

Now, it catches the ValueError exception, but not other exceptions. If we want this handler to address more than one type of exception, we can include a parenthesized tuple after the except with the exceptions.

try:
    # some code
except (ValueError, KeyboardInterrupt):
    # some code

Or, if we want to execute different blocks of code depending on the exception, you can have multiple except blocks.

try:
    # some code
except ValueError:
    # some code
except KeyboardInterrupt:
    # some code