How to flatten only one sub list of list of lists
Peter Otten
__peter__ at web.de
Wed Mar 1 02:41:06 EST 2017
Sayth Renshaw wrote:
> How can I flatten just a specific sublist of each list in a list of lists?
>
> So if I had this data
>
>
> [ ['46295', 'Montauk', '3', '60', '85', ['19', '5', '1', '0
> [ [$277790.00']],
> ['46295', 'Dark Eyes', '5', '59', '83', ['6', '4', '1', '0
> [$105625.00']], '46295', 'Machinegun Jubs', '6', '53', '77', ['6',
> ['2', '1', '1 $71685.00']], '46295', 'Zara Bay', '1', '53', '77',
> [['12', '2', '3', '3 $112645.00']]]
>
>
> How can I make it be
>
>
> [ ['46295', 'Montauk', '3', '60', '85', '19', '5', '1', '0 $277790.00'],
> ['46295', 'Dark Eyes', '5', '59', '83', '6', '4', '1', '0
> [$105625.00'], '46295', 'Machinegun Jubs', '6', '53', '77', '6', '2',
> ['1', '1 $71685.00'], '46295', 'Zara Bay', '1', '53', '77', '12', '2',
> ['3', '3 $112645.00']]
>
> Been looking around but most solutions just entirely flatten everything.
> This was popular on SO but yeah it flattens everything I want to be more
> selective
>
> def flatten(lst):
> for elem in lst:
> if type(elem) in (tuple, list):
> for i in flatten(elem):
> yield i
> else:
> yield elem
>
> What I am thinking is that if for each list the sublist should be at index
> 1, so
>
> [0][1]
> [1][1]
> [2][1]
>
> for item in list:
> item[1] - somehow flatten.
>
> Thoughts?
Replace the slice row[index:index+1] with row[index], either by building a new list or in place:
>>> def show(data):
... for item in data: print(item)
...
>>> def flatten_one(rows, index):
... return [r[:index] + r[index] + r[index+1:] for r in rows]
...
>>> show(data)
['46295', 'Montauk', '3', '60', '85', ['19', '5', '1', '0 $277790.00']]
['46295', 'Dark Eyes', '5', '59', '83', ['6', '4', '1', '0 $105625.00']]
['46295', 'Machinegun Jubs', '6', '53', '77', ['6', '2', '1', '1 $71685.00']]
['46295', 'Zara Bay', '1', '53', '77', ['12', '2', '3', '3 $112645.00']]
>>> show(flatten_one(data, 5))
['46295', 'Montauk', '3', '60', '85', '19', '5', '1', '0 $277790.00']
['46295', 'Dark Eyes', '5', '59', '83', '6', '4', '1', '0 $105625.00']
['46295', 'Machinegun Jubs', '6', '53', '77', '6', '2', '1', '1 $71685.00']
['46295', 'Zara Bay', '1', '53', '77', '12', '2', '3', '3 $112645.00']
>>> def flatten_inplace(rows, index):
... for row in rows:
... row[index:index+1] = row[index]
...
>>> flatten_inplace(data, 5)
>>> show(data)
['46295', 'Montauk', '3', '60', '85', '19', '5', '1', '0 $277790.00']
['46295', 'Dark Eyes', '5', '59', '83', '6', '4', '1', '0 $105625.00']
['46295', 'Machinegun Jubs', '6', '53', '77', '6', '2', '1', '1 $71685.00']
['46295', 'Zara Bay', '1', '53', '77', '12', '2', '3', '3 $112645.00']
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