CODEWITHSUNDEEP
python
Tapajyoti Ghosh
Tapajyoti Ghosh

Reputation: 19

How do I enforce exception handling in the condition of a for loop?

I am trying to loop the object check which is a specific database obtained from the OpenLCA software. This database has a certain bug in some instance of it. Whenever I am running the for statement, after looping through many instances, when the code encounters buggy instance it throws me a error in the for loop condition -

for i in check:

How do I enforce exception handling on the for loop condition statement as shown. Please help.

Just to be very specific - the error is not thrown for the statement inside the loop. Its thrown in for i in check statement itself. So having try inside the loop does not help me for this case. 

    check = client.get_all(olca.Process)
    for i in check:
       #print(type(i))
       process = i.default_allocation_method
       name = i.name
       print(name)

File "U:/Desktop/Box/Box Sync/Research_compile/electricitylci/pythonapiopenlca.py", line 101, in for i in check:

File "C:\ProgramData\Anaconda3\lib\site-packages\olca\ipc.py", line 105, in get_all e.from_json(r)

File "C:\ProgramData\Anaconda3\lib\site-packages\olca\schema.py", line 1882, in from_json self.default_allocation_method = AllocationType(val)

File "C:\ProgramData\Anaconda3\lib\enum.py", line 291, in call return cls.new(cls, value)

File "C:\ProgramData\Anaconda3\lib\enum.py", line 533, in new return cls.missing(value)

File "C:\ProgramData\Anaconda3\lib\enum.py", line 546, in missing raise ValueError("%r is not a valid %s" % (value, cls.name))

ValueError: 'NO_ALLOCATION' is not a valid AllocationType

Upvotes: 0

Views: 101

Answers (2)

Mojtaba Kamyabi
Mojtaba Kamyabi

Reputation: 3620

use try and except inside your for loop like this:

for i in check:
   try:
       process = i.default_allocation_method
       name = i.name
       print(name)
   except Exception as e:
       print("error is: {}".format(e))

UPDATE: If your error raised in for loop statement and you want to continue your for loop execution even after error was raise, you can replace it with while loop (if check has len and is not an iterator) and handle exceptions like this:

check = client.get_all(olca.Process)
i = 0
while i < len(check):  # or other function that returns length of check
    try:
        process = check[i].default_allocation_method
        name = check[i].name
        print(name)
    except Exception as e:
        print("error is: {}".format(e))
    finally:
        i += 1

if check is an iterator you can use generator function (see @tripleee answer)

Upvotes: 2

tripleee
tripleee

Reputation: 189938

There isn't really a way to isolate a try to only cover the for statement. Perhaps wrap it something like this:

def wrap_next(getter):
    while True:
        try:
           yield getter.next()
        except ValueError:
            howl(misery, desperation)

for i in wrap_next(check) 
    ... Do things

Upvotes: 4

Related Questions