diff --git a/README.md b/README.md index e5e7cd8..0ec38b4 100644 --- a/README.md +++ b/README.md @@ -1306,36 +1306,63 @@ from functools import partial LogicOp = Enum('LogicOp', {'AND': partial(lambda l, r: l and r), 'OR' : partial(lambda l, r: l or r)}) ``` +* **Another solution in this particular case, is to use `'and_'` and `'or_'` functions from module [operator](#operator) as values.** Exceptions ---------- + +### Basic Example ```python -while True: - try: - x = int(input('Please enter a number: ')) - except ValueError: - print('Oops! That was no valid number. Try again...') - else: - print('Thank you.') - break +try: + +except : + +``` + +### Complex Example +```python +try: + +except : + +except : + +else: + +finally: + +``` + +### Catching Exceptions +```python +except : +except as : +except (, , ...): +except (, , ...) as : +``` +* **Also catches subclasses of the exception.** + +### Raising Exceptions +```python +raise +raise () +raise () +raise (, , ...) ``` -### Raising Exception +#### Useful built-in exceptions: ```python -raise ValueError('A very specific message!') +raise ValueError('Argument is of right type but inappropriate value!') +raise TypeError('Argument is of wrong type!') +raise RuntimeError('None of above!') ``` -### Finally +#### Re-raising caught exception: ```python ->>> try: -... raise KeyboardInterrupt -... finally: -... print('Goodbye, world!') -Goodbye, world! -Traceback (most recent call last): - File "", line 2, in -KeyboardInterrupt +except : + + raise ``` ### Common Built-in Exceptions @@ -1361,7 +1388,15 @@ BaseException +-- ValueError # When an argument is of right type but inappropriate value. +-- UnicodeError # Raised when encoding/decoding strings from/to bytes fails. ``` -* **Appropriate built-in exceptions for user to rise are: 'ValueError', 'TypeError' and 'RuntimeError'.** + +### User-defined Exceptions +```python +class MyError(Exception): + pass + +class MyInputError(MyError): + pass +``` Print diff --git a/index.html b/index.html index f072cd3..cb36d39 100644 --- a/index.html +++ b/index.html @@ -1210,28 +1210,52 @@ Cutlery = Enum('Cutlery', {'LogicOp', {'AND': partial(lambda l, r: l and r), 'OR' : partial(lambda l, r: l or r)}) +
    +
  • Another solution in this particular case, is to use 'and_' and 'or_' functions from module operator as values.
    • +

#Exceptions

-
while True:
-    try:
-        x = int(input('Please enter a number: '))
-    except ValueError:
-        print('Oops!  That was no valid number.  Try again...')
-    else:
-        print('Thank you.')
-        break
+
Basic Example

+
try:
+    <code>
+except <exception>:
+    <code>
 

-
Raising Exception

-
raise ValueError('A very specific message!')
+
Complex Example

+
try:
+    <code_1>
+except <exception_a>:
+    <code_2_a>
+except <exception_b>:
+    <code_2_b>
+else:
+    <code_2_c>
+finally:
+    <code_3>
+

+
Catching Exceptions

+
except <exception>:
+except <exception> as <name>:
+except (<exception_1>, <exception_2>, ...):
+except (<exception_1>, <exception_2>, ...) as <name>:
 

-
Finally

-
>>> try:
-...     raise KeyboardInterrupt
-... finally:
-...     print('Goodbye, world!')
-Goodbye, world!
-Traceback (most recent call last):
-  File "<stdin>", line 2, in <module>
-KeyboardInterrupt
+
    
+
  • Also catches subclasses of the exception.
    • 
+

+
Raising Exceptions

+
raise <exception>
+raise <exception>()
+raise <exception>(<el>)
+raise <exception>(<el_1>, <el_2>, ...)
+

+
Useful built-in exceptions:

+
raise ValueError('Argument is of right type but inappropriate value!')
+raise TypeError('Argument is of wrong type!')
+raise RuntimeError('None of above!')
+

+
Re-raising caught exception:

+
except <exception>:
+    <code>
+    raise
 

 
Common Built-in Exceptions

 
BaseException
@@ -1255,9 +1279,13 @@ KeyboardInterrupt
       +-- ValueError              # When an argument is of right type but inappropriate value.
            +-- UnicodeError       # Raised when encoding/decoding strings from/to bytes fails. 
 

-
    
-
  • Appropriate built-in exceptions for user to rise are: 'ValueError', 'TypeError' and 'RuntimeError'.
    • 
-

+
User-defined Exceptions

+
class MyError(Exception):
+    pass
+
+class MyInputError(MyError):
+    pass
+

 
#Print

 
print(<el_1>, ..., sep=' ', end='\n', file=sys.stdout, flush=False)