Python - exception handling

Exception handling

Exceptions are classes. You can define your own by inheriting from Exception class.

try:
    statements

except Exception_type1 as e1:
    handling statements

except Exception_type2 as e2:
    specific handling statements

except Exception as generic_ex:
    generic handling statements

else:
    some more statements  # executes if no exceptions were fired

finally:
    default statements which will always be executed  # put logic such as conn close / mem release statements here
In [13]:
try:
    img2 = ImageryObject("user\img\file2.img")
    img2.display()
except:
    print("something bad happened")
image is displayed
In [14]:
try:
    img2 = ImageryObject("user\img\file2.img")
    img2.display()
except:
    print("something bad happened")
else:
    print("else block")
finally:
    print("finally block")
image is displayed
else block
finally block
In [15]:
try:
    img2 = ImageryObject()
    img2.display()
except:
    print("something bad happened")
else:
    print("else block")
finally:
    print("finally block")
something bad happened
finally block
In [21]:
try:
    img2 = ImageryObject()
    img2.display()

except Exception as ex:
    print("something bad happened")
    print("exactly what whent bad? : " + str(ex))
something bad happened
exactly what whent bad? : __init__() missing 1 required positional argument: 'file_path'
In [22]:
try:
    img2 = ImageryObject('path')
    img2.dddisplay()

except TypeError as terr:
    print("looks like you forgot a parameter")
except Exception as ex:
    print("nope, it went worng here: " + str(ex))
nope, it went worng here: 'ImageryObject' object has no attribute 'dddisplay'
In [ ]: