37-Exception_handing_1.py

'''
author : Jaydatt Patel

Exception handing
syntax :
        try:
            <try clause code block>
        except <ErrorType> as err_variable:
            <exception handler code block>
        except <ErrorType> as err_variable:
            <exception handler code block>
            ..
            ..
            ..


# Note : Whenever you occur exception, you must pass to Exception class or perticular define class like IndexError, ZeroDivisionError. 
# You can not pass divide by zero exception to IndexError class, It must be passed to ZeroDivisionError class. 
#  If You pass divide by zero exception to IndexError class instead of ZeroDivisionError class, Then program terminated and rest of the program will not execute. 


# Standard Exceptions :

- StandardError : Base class for all built-in exceptions except StopIteration and SystemExit.
- ImportError : Raised when an import statement fails.
- SyntaxError : Raised when there is an error in Python syntax.
- IndentationError : Raised when indentation is not specified properly.
- NameError : Raised when an identifier is not found in the local or global namespace.
- UnboundLocalError : Raised when trying to access a local variable in a function or method but no value has been assigned to it.
- TypeError : Raised when an operation or function is attempted that is invalid for the specified data type.
- LookupError : Base class for all lookup errors.
- IndexError : Raised when an index is not found in a sequence.
- KeyError : Raised when the specified key is not found in the dictionary.
- ValueError : Raised when the built-in function for a data type has the valid type of arguments, but the arguments have invalid values specified.
- RuntimeError : Raised when a generated error does not fall into any category.
- MemoryError : Raised when a operation runs out of memory.
- RecursionError : Raised when the maximum recursion depth has been exceeded.
- SystemError : Raised when the interpreter finds an internal problem, but when this error is encountered the Python interpreter does not exit.


# Math Exceptions :

- ArithmeticError : Base class for all errors that occur for numeric calculation. You know a math error occurred, but you don't know the specific error.
- OverflowError : Raised when a calculation exceeds maximum limit for a numeric type.
- FloatingPointError : Raised when a floating point calculation fails.
- ZeroDivisonError : Raised when division or modulo by zero takes place for all numeric types.


# I/O Exceptions :

- FileNotFoundError : Raised when a file or directory is requested but doesn't exist.
- IOError : Raised when an input/ output operation fails, such as the print statement or the open() function when trying to open a file that does not exist. Also raised for operating system-related errors.
- PermissionError : Raised when trying to run an operation without the adequate access rights.
- EOFError : Raised when there is no input from either the raw_input() or input() function and the end of file is reached.
- KeyboardInterrupt : Raised when the user interrupts program execution, usually by pressing Ctrl+c.

# Other Exceptions :

- Exception : Base class for all exceptions. This catches most exception messages.
- StopIteration : Raised when the next() method of an iterator does not point to any object.
- AssertionError : Raised in case of failure of the Assert statement.
- SystemExit : Raised when Python interpreter is quit by using the sys.exit() function. If not handled in the code, it causes the interpreter to exit.
- OSError : Raises for operating system related errors.
- EnvironmentError : Base class for all exceptions that occur outside the Python environment.
- AttributeError : Raised in case of failure of an attribute reference or assignment.
- NotImplementedError :  Raised when an abstract method that needs to be implemented in an inherited class is not actually implemented.

'''

print("----------(1)----------")
try:
    items = ['a', 'b']
    third = items[2]
    print("This won't print")
except Exception as err:
    print("Got Error : " , err)

print("continuing")

print("----------(2)----------")
try:
    x = 5
    y = x/0
    print("This won't print, either")
except Exception as err:
    print("Got error : ",err)

print("continuing again")


print("----------(4)----------")
dic = {'name':'Rahul','Age' : 20}
try : 
    for key in dic:
        dic[key]
    dic['Mobile'] # key not exist
except Exception as err:
    print("Got error : ", err)

print("continuing again")