Python Style Question

[Rafael Romero Carmona]

2014-10-29 12:25 GMT+01:00 Martin Kemp <martin.kemp at ingg.com>:
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> On 29/10/2014 10:45, Anton wrote:
>> Let's say I have an incoming list of values *l*. Every element of
>> *l* can be one of the following options: 1) an integer value 2) a
>> string in form of '<int_value>', e.g. '7' 3) a string with a json
>> serialization of an integer value, e.g. '"7"' 4) something else
>> that should be ignored
>>
>> I need to transform this list into another list with values from
>> options 1)-3) coerced to int. The code below should do this.
>>
>>
>> Variant 1 ===
>>
>> values = [] for c in l: # Case 1) or 2) try: c_int = int(c) except
>> ValueError: pass else: values.add(c_int) continue
>>
>> # Case 3) try: c_int = int(json.loads(c)) except ValueError: pass
>> else: values.add(c_int) continue
>>
>> ===
>>
>> Is this code ugly? Does it follow EAFP? Am I missing something in
>> language best practice?
>>
>> Or maybe below is more preferable way with a nested try...except
>> clause?
>>
>> Variant 2 === values = [] for c in l: # Case 1) or 2) try: c_int =
>> int(c) except ValueError:  # Case 3) try: c_int =
>> int(json.loads(c)) except ValueError: pass else: values.add(c_int)
>> continue  else: values.add(c_int) continue ===
>>
>> Thanks, Anton.
>>
>>
>
> Your first example is perfectly fine and is EAFP
>

Actually it doesn't work because there is no add function and it
doesn't catch the TypeError function to ignore other exceptions than
ValueError. Doesn't it? I tested in Python 2.7.6 and 3.4.

> Personally, I prefer to avoid nesting when it's not necessary.
>
> - --
> Martin Kemp (martin.kemp at ingg.com)
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