Nested lists python

Question

Can anyone tell me how can I call for indexes in a nested list   Generally I just write    for i in range  list    but what if I have a list with nested lists as below   Nlist     2 2 2   3 3 3   4 4 4        and I want to go through the indexes of each one separately

User · Answer

You can do this  Adapt it to your situation     for l in Nlist        for item in l          print item

User · Answer

I think you want to access list values and their indices simultaneously and separately   l     2 2 2   3 3 3   4 4 4   5 5 5   l len   len l  l item len   len l 0   for i in range l len       for j in range l item len           print f List  i    j      l i  j

User · Answer

The question title is too wide and the author s need is more specific  In my case  I needed to extract all elements from nested list like in the example below   Example   input - gt   1 2  3 4   output - gt   1 2 3 4    The code below gives me the result  but I would like to know if anyone can create a simpler answer   def get elements from nested list l  new l       if l is not None          e   l 0          if isinstance e  list               get elements from nested list e  new l          else              new l append e          if len l   gt  1              return get elements from nested list l 1    new l          else              return new l   Call of the method  l    1 2  3 4   new l       get elements from nested list l  new l

User · Answer

If you really need the indices you can just do what you said again for the inner list   l     2 2 2   3 3 3   4 4 4   for index1 in xrange len l        for index2 in xrange len l index1             print index1  index2  l index1  index2    But it is more pythonic to iterate through the list itself   for inner l in l      for item in inner l          print item   If you really need the indices you can also use enumerate   for index1  inner l in enumerate l       for index2  item in enumerate inner l           print index1  index2  item  l index1  index2

User · Answer

n     1  2  3    4  5  6  7  8  9   def flatten lists     results        for numbers in lists      for numbers2 in numbers          results append numbers2     return results print flatten n    Output  n    1 2 3 4 5 6 7 8 9

User · Answer

Try this setup   a      a   b   c      d   e     f   g   h      To print the 2nd element in the 1st list   b    use print a 0  1  - For the 2nd element in 3rd list   g    print a 2  1   The first brackets reference which nested list you re accessing  the second pair references the item in that list

[python] Nested lists python

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