iterate through an irregular nested list in Python

[Pieter van Oostrum]

sinndhhu at gmail.com writes:

> Hi All,
> I am new to python.
> I have a irregular nested lists in a list.
> Please help me to iterate through each element.
>
> Thanks much in advance.
>
> Sample Ex 
>
> aList = [[2,'jkj'],[],[],['kite',88,'ooo','pop','push','pull'],['hello']]
>
> expected output:
> 2,jkj,,,kite,88,ooo,pop,push,pull,hello
>

Use a recursive iterator/generator:
It becomes a bit peculiar because you want special treatment for empty lists inside,
but otherwise it is quite standard Python:

aList = [[2,'jkj'],[],[],['kite',88,'ooo','pop','push','pull'],['hello']]

def reclist(aList):
    for item in aList:
        if isinstance(item, list):
            if item == []:
                yield ''
            else:
                yield from reclist(item)
        else:
            yield item

for i in reclist(aList):
    print(i, end=',')

This gives you an extra comma at the end, unfortunately.
But it is the pattern for other types of processing.

Or use it like this:

print (','.join(str(i) for i in reclist(aList)))

-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]