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Answer 1

A:

data = '''[["Name1","ID1","DDY1", "CALL1", "WHEN1"], ["Name2","ID2","DDY2", "CALL2", "WHEN2"]]'''
data = eval(data) #this is either eval or raw_input, I'm not sure
for x in data:
    print x[0]

This is something off the top of my head, I'm at work and don't have python installed so I can't test it out for you.

Jeroen Pelgrims 2010-05-06 08:32:01

Tried it. It prints every character on it's own line

j00niner 2010-05-06 08:35:38

That won't work. It will print each character in the string data on its own line.

wump 2010-05-06 08:35:51

Yea, i mistaked list() with eval() or raw_input(), corrected my mistake.

Jeroen Pelgrims 2010-05-06 08:36:35

This would probably work, but eval is *dangerous*. If you don't validate the string well, the site could execute any python code in your context.

wump 2010-05-06 08:39:43

Answer 2

+6 A:

Hope I understood well.

>>> import json
>>> a = json.loads('[["Name1","ID1","DDY1", "CALL1", "WHEN1"], ["Name2","ID2","DDY2", "CALL2", "WHEN2"]]')
>>> [x[0] for x in a]
[u'Name1', u'Name2']
>>>

Marco Mariani 2010-05-06 08:33:57

+1 for simply using the JSON parser

wump 2010-05-06 08:34:54

"No JSON object could be decoded"

j00niner 2010-05-06 08:38:39

Then you need to show the full string. It could be a mangled json or something else entirely.

Marco Mariani 2010-05-06 08:44:45

You may need to strip a trailing comma after the last grouping. Throw the string into jslint - it will tell you what's wrong. Then massage the string so it works and do the above. You should *really* avoid using eval on a string taken from another website.

adamnfish 2010-05-06 08:45:13

Also, the string you are passing to json.loads should be a unicode object. Check that, or decode appropriately from utf-8 or whatever encoding.

Marco Mariani 2010-05-06 08:51:26

Problem at line 1 character 194: Expected '(end)' and instead saw ';'.

j00niner 2010-05-06 08:52:36

strip the ";" off the end.

Gabriel 2010-05-06 08:55:38

Do I put [u'Name1', u'Name2'] in my IDE also or is that only for shell?

j00niner 2010-05-06 08:59:55

I mean [x[0] for x in a]

j00niner 2010-05-06 09:05:25

oh, it was just to show the output, if the 'Name' strings are what you are after.

Marco Mariani 2010-05-06 09:17:19

Answer 3

+2 A:

import ast
y = ast.literal_eval(input)
[x[0] for x in y]

Thanks to @stephan for pointing me in the right direction with ast.literal_eval. As described by the documentaion:

Safely evaluate an expression node or a string containing a Python expression. The string or node provided may only consist of the following Python literal structures: strings, numbers, tuples, lists, dicts, booleans, and None.

This can be used for safely evaluating strings containing Python expressions from untrusted sources without the need to parse the values oneself.

Note: this is new functionality in Python 2.6.

Gabriel 2010-05-06 08:39:34

Suggest `ast.literal_eval()` instead of `eval`.

stephan 2010-05-06 08:47:46

Fixed, thanks. I knew it was around and I was searching for it. http://docs.python.org/library/ast.html ftw.

Gabriel 2010-05-06 08:53:12

You are welcome. Another tiny improvement: `str` is a built-in class, hence I wouldn't use this name in the list comprehension.

stephan 2010-05-06 09:35:17

fixed. Thanks again stephan.

Gabriel 2010-05-06 09:54:58

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Parsing groupings of strings (Python)

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