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 wanted to ignore that particular record. So I did this

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

but it does not continue further. How can I overcome this problem

Edit: Error trace added

    Traceback (most recent call last):
  File "modify.py", line 22, in <module>
    for record in reader:
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/datafile.py", line 362, in next
    datum = self.datum_reader.read(self.datum_decoder) 
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 445, in read
    return self.read_data(self.writers_schema, self.readers_schema, decoder)
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 490, in read_data
    return self.read_record(writers_schema, readers_schema, decoder)
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 690, in read_record
    field_val = self.read_data(field.type, readers_field.type, decoder)
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 468, in read_data
    return decoder.read_utf8()
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 233, in read_utf8
    return unicode(self.read_bytes(), "utf-8")
UnicodeDecodeError: 'utf8' codec can't decode byte 0xb4 in position 14: invalid start byte

could it be due to the fact that the file was corrupted?

Edit2: As per suggestion in answers to go through iterobject I modified code and got this error

    Traceback (most recent call last):
  File "modify.py", line 28, in <module>
    print next(iterobject)["filepath"]
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/datafile.py", line 362, in next
    datum = self.datum_reader.read(self.datum_decoder) 
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 445, in read
    return self.read_data(self.writers_schema, self.readers_schema, decoder)
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 490, in read_data
    return self.read_record(writers_schema, readers_schema, decoder)
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 690, in read_record
    field_val = self.read_data(field.type, readers_field.type, decoder)
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 468, in read_data
    return decoder.read_utf8()
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 233, in read_utf8
    return unicode(self.read_bytes(), "utf-8")
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 226, in read_bytes
    return self.read(self.read_long())
  File "/usr/lib/python2.6/site-packages/avro-1.7.7-py2.6.egg/avro/io.py", line 184, in read_long
    b = ord(self.read(1))
TypeError: ord() expected a character, but string of length 0 found

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.