How to get another variable type from sql query

Question

From this query...

self.cur.execute("""SELECT pub FROM "20091229"
                 GROUP BY pub ORDER BY pub""")

I get the following list with tuples back.

>>[(1,), (2,), (3,)]

But I need only a list or a list without decimal points in the tuples. Something like these:

[1, 2, 3]

or

[(1), (2), (3)]

Thanks.

[(1,), (2,), (3,)] - these are not decimal points (commas). These are tuple elements delimiters. — eumiro
– eumiro, Commented Jul 13, 2011 at 13:58

Artsiom Rudzenka · Accepted Answer · 2011-07-13 13:47:04Z

1

It will be better if you tell us what module do you use to work with db. Also i am not sure but your query can be optimized to something like this 'SELECT DISTINCT pub FROM "20091229" ORDER BY pub'

I know that nobody here likes reduce but it could be also used here:

from operator import add

reduce(lambda res,x: add(res, x), [(1,), (2,), (3,)])

OR in case there could be only list of single item tuples:

from operator import itemgetter
map(itemgetter(0), [(1,), (2,), (3,)])

answered Jul 13, 2011 at 13:47

Artsiom Rudzenka

29.3k5 gold badges36 silver badges53 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

The_Fox Over a year ago

Maybe it is not the best way to solve it but it works. :) Now, I just get a tuple back: (1, 2, 3). Thank you very much.

Artsiom Rudzenka Over a year ago

Thank you, @The_Fox - there are a lot of ways to do things in python and selecting the best is always depends only from you.

orlp · Accepted Answer · 2011-07-13 13:04:52Z

1

What about this?

li = [tup[0] for tup in li]

Please note, a tuple get's written like this (1,), because (1) would imply mathematical brackets. Also, it seems you are trying to print a list, consider using a dedicated printing function.

answered Jul 13, 2011 at 13:04

orlp

119k39 gold badges226 silver badges324 bronze badges

2 Comments

The_Fox Over a year ago

I need a list because i want to use this list in a later sql query as variable and with the decimal points i get an error.

orlp Over a year ago

@The_Fox: The problem is is that you are using str(li). Consider proper formatting the list.

Collectives™ on Stack Overflow

How to get another variable type from sql query

2 Answers 2

2 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related