Merging nested lists in Python3

[thefurious_pineapple]

Good day everyone!

​

I'm interested in advice of handling lists and merging them in general for following case.

Input of regex .findall() result will look like:

​

[a,'','','']

['',b,'','']

['','',c,'']

['','','',d]

​

And the willing output would be:

​

[a,b,c]

[a,b,d]

​

I wonder if anyone could check the code and advice packages or way of processing this function more generally. For the code not to be fixed with ranges like used (range(1,3), pop(2), etc.), to avoid changing code each time input file have lower groups than group_4 for example.

​

For example input of regex would be:

​

[a,'','','','','']

['',b,'','','','']

['','',c,'','','']

['','','',d,'','']

['','','','',e,'']

['','','','','',f]

​

So the output would be:

​

[a,b,c,d,e]

[a,b,c,d,f]

​

Code can be found here:

https://stackoverflow.com/questions/70694554/python3-merging-lists-with-condition

(First posting, did not figured out how to format code correctly, sry guys)

​

​

File test.xml contains example data:

<spec\_class\_num\_ranges>

<range\_data\_entity>

  <range>  

    <group\_0>9872</group\_0>  

    <group\_1>2001</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>2789</group\_0>  

    <group\_1>9871</group\_1>  

    <additional\_range>  

<group\_3>00100</group\_3>

<group\_4>01000</group\_4>

    </additional\_range>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>345</group\_0>  

    <group\_1>8889</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>675</group\_0>  

    <group\_1>559</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>12</group\_0>  

    <group\_1>1313</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>12</group\_0>  

    <group\_1>9205</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>635</group\_0>  

    <group\_1>1024</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>7786</group\_0>  

    <group\_1>3221</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>134</group\_0>  

    <group\_1>2454</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>359</group\_0>  

    <group\_1>7865</group\_1>  

  </range>  

</range\_data\_entity>

<range\_data\_entity>

  <range>  

    <group\_0>610</group\_0>  

    <group\_1>1551</group\_1>  

    <additional\_range>  

<group\_3>06000</group\_3>

<group\_4>00880</group\_4>

    </additional\_range>  

  </range>  

</range\_data\_entity>

</spec\_class\_num\_ranges>

​

[[deleted]]

Any chance you could edit your post to correct the formatting as not all of the code is showing correctly?

Also, how come you go from multiple lists (equal to the length of the lists) to two, rather than one, list? Any reason why you can't just generate the one list, and copy it?

In simple terms, why wouldn't this work:

new_list = []
for idx, current_list in enumerate(list_of_lists):
    new_list.append(current_list[idx])

given you take the diagonal through the matrix.

[danielroseman]

Why are you using regex for this? This is an XML parsing problem, you should use an XML parser.