python: try/except around whole module

Besides, wrapping the entire thing in a try...except won't work, as that will only be catching exceptions that would occur during the definition of the classes/functions (when your module is loaded/imported). For example,

# Your python library
try:
def foo():
   raise Exception('foo exception')
return 42
except Exception as e:
   print 'Handled: ', e

# A consumer of your library
foo()

another option:

def raises( * exception_list):
   def wrap(f):
   def wrapped_f( * x, ** y):
   try:
   f( * x, ** y)
except Exception as e:
   if not isinstance(e, tuple(exception_list)):
   print('send mail')
# send mail
raise
return wrapped_f
return wrap

usage:

@raises(MyException)
def foo():
   ...

Suggestion : 2

8.3. Handling Exceptions,8.4. Raising Exceptions,8. Errors and Exceptions,8.5. Exception Chaining

>>> while True print('Hello world')
File "<stdin>", line 1
   while True print('Hello world')
   ^
   SyntaxError: invalid syntax

>>> 10 * (1/0)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
      ZeroDivisionError: division by zero
      >>> 4 + spam*3
      Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
            NameError: name 'spam' is not defined
            >>> '2' + 2
            Traceback (most recent call last):
            File "<stdin>", line 1, in <module>
                  TypeError: can only concatenate str (not "int") to str

>>>
while True:
   ...
   try:
   ...x = int(input("Please enter a number: "))
   ...
   break
   ...except ValueError:
   ...print("Oops!  That was no valid number.  Try again...")
   ...

...except(RuntimeError, TypeError, NameError):
   ...pass

class B(Exception):
   pass

class C(B):
   pass

class D(C):
   pass

for cls in [B, C, D]:
   try:
   raise cls()
except D:
   print("D")
except C:
   print("C")
except B:
   print("B")

import sys

try:
f = open('myfile.txt')
s = f.readline()
i = int(s.strip())
except OSError as err:
   print("OS error: {0}".format(err))
except ValueError:
   print("Could not convert data to an integer.")
except BaseException as err:
   print(f "Unexpected {err=}, {type(err)=}")
raise

Suggestion : 3

Last Updated : 28 Jan, 2022

Syntax:

try:
# Some Code
except:
   # Executed
if error in the
#
try block

Output :

('Yeah ! Your answer is :', 1)

Syntax:

try:
# Some Code
except:
   # Executed
if error in the
#
try block
else:
   # execute
if no exception

Suggestion : 4

Date and Time in Python,Any type of exception can be raised:,The program continues execution if no exception has been thrown.,You can write different logic for each type of exception that happens:

 >>> dir(builtins)

try: <do something>except Exception: <handle the error>

try: 1 / 0 except ZeroDivisionError: print('Divided by zero') print('Should reach here')

 $ python3 example.pyDivided by zeroShould reach here

Suggestion : 5

In Python programming, exception handling allows a programmer to enable flow control. And it has no. of built-in exceptions to catch errors in case your code breaks. Using try-except is the most common and natural way of handling unexpected errors along with many more exception handling constructs. In this tutorial, you’ll get to explore some of the best techniques to use try-except in Python.,Hence, we’ll cover broader problems and provide solutions in this post. Please note that exception handling is an art which brings you immense powers to write robust and quality code. So, brace to read some keynotes on exceptions along with the best ways to handle them.,Why use Exceptions? They not only help solve popular problems like race conditions but are also very useful in controlling errors in areas like loops, file handling, database communication, network access and so on.,Sometimes, you may need a way to allow any arbitrary exception and also want to be able to display the error or exception message.

It is easily achievable using the Python exceptions. Check the below code. While testing, you can place the code inside the try block in the below example.

try:
#your code
except Exception as ex:
   print(ex)

You can catch multiple exceptions in a single except block. See the below example.

except(Exception1, Exception2) as e:
   pass

There are many ways to handle multiple exceptions. The first of them requires placing all the exceptions which are likely to occur in the form of a tuple. Please see from below.

try:
file = open('input-file', 'open mode')
except(IOError, EOFError) as e:
   print("Testing multiple exceptions. {}".format(e.args[-1]))

The last but not the least is to use the except without mentioning any exception attribute.

try:
file = open('input-file', 'open mode')
except:
   # In
case of any unhandled error,
throw it away
raise

See the below example code.

try:
# Intentionally raise an exception.
raise Exception('I learn Python!')
except:
   print("Entered in except.")
# Re - raise the exception.
raise