Catch error in a for loop python

Question

I have a for loop on an avro data reader object

for i in reader:
    print i

then I got a unicode decode error in the for statement so I wa

Answer 1

If your error is in for i in. Then try this, it will skip element in iterator if UnicodeDecodeError occurs.

iterobject = iter(reader)
while iterobject:
    try:
        print(next(iterobject))
    except StopIteration:
        break
    except UnicodeDecodeError:
        pass

Answer 2

You need the try/except inside the loop:

    for i in reader:
       try: 
           print i
       except UnicodeEncodeError:
           pass

By the way it's good practice to specify the specific type of error you're trying to catch (like I did with except UnicodeEncodeError:, since otherwise you risk making your code very hard to debug!

Answer 3

You can except the specific error, and avoid unknown errors to pass unnoticed.

Python 3.x:

try:
    for i in reader:
        print i
except UnicodeDecodeError as ue:
    print(str(ue))

Python 2.x:

try:
    for i in reader:
        print i
except UnicodeDecodeError, ue:
    print(str(ue))

By printing the error it's possible to know what happened. When you use only except, you except anything (And that can include an obscure RuntimeError), and you'll never know what happened. It can be useful sometimes, but it's dangerous and generally a bad practice.