Python try exception tutorial

In python, try except statements are used to handle exceptions in the code, when a error occurs it will break the program to prevent it and to log the error, this will be really helpful when running the code in production where it might end up with multiple error of different cases.

Python support different exception capture method, let see the syntax of the try statement.

try:
    # try code block
    pass
except:
    print("except")
else:
    print("else")
finally:
    print("finally")

Python try and except block

try section where the main logic of the code will be written.
except block is used to capture the error occurred in try block

try:
    x = 1 / 0
except:
    print("except")

Output:
except

capture exception error

try:
    x = 1 / 0
except Exception as e:
    print("except:", e)

Output:
except: division by zero

else block

We already knew else is used in if statement, it will be executed when if statement is not True. Same kind logic applied here, when there is not exception occurred then the else block will executed after completing the try block code.

try:
    x = 1 / 5
except Exception as e:
    print("except:", e)
else:
    print("else")

Output:
else

finally block

finally block will always execute regardless of the exception occurrence

try:
    x = 1 / 5
except Exception as e:
    print("except:", e)
else:
    print("else")
finally:
    print("finally")

Output:
else
finally

Capture Specific Exception in Python

Python support different exception types such as OSError, ValueError, ZeroDivisionError, etc

try:
    x = 1 / 0
except OSError as e:
    print("OSError:", e)
except ValueError as e:
    print("ValueError:", e)
except ZeroDivisionError as e:
    print("ZeroDivisionError:", e)
except Exception as e:
    print("except:", e)

Output:
ZeroDivisionError: division by zero

since this error is occurred because the value is divided by zero it will be captured in ZeroDivisionError

Python Catch multiple exceptions in one line

try:
    x = 1 / 0
except (OSError, ValueError, ZeroDivisionError) as e:
    print("ERROR:", e)
except Exception as e:
    print("except:", e)

Output:
ERROR: division by zero

Note: multiple exception types must be parenthesized

you can ask then what is the use of next except block, suppose we don't what kind of error will occurs then this block can be used to capture all type of exceptions.

try:
    print(y)
except (OSError, ValueError, ZeroDivisionError) as e:
    print("ERROR:", e)
except Exception as e:
    print("except:", e)

Output:
except: name 'y' is not defined

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