python - Unable to insert values into a list at the correct index -


i receive list of numbers , want sort them. input looks this: 

i:1,3,5,8 n:2 t:4,7 a:6 v:9

and comes in form of txt file.

the code looks this:

flat_list = [item sublist in decks item in sublist] p = []   x in range(len(flat_list)):     nr = flat_list[x][0]     o = nr -1     p.insert((o),(flat_list[x][1]))  print(p)

which gives output:

[(1, 'i'), (2, 'n'), (3, 'i'), (4, 't'), (5, 'i'), (6, 'a'), (8, 'i'), (7,   't'), (9, 'v')]

which want, except 7 , 8. do wrong ?

you declare empty list:

p = []

but call list.insert on it. this, unfortunately, leads unintended side effects. observe:

in [209]: p.insert(999, 0)  in [210]: p out[210]: [0]

which inserted @ 0th position, despite fact wanted in (999 + 1)th place. sort of thing reason see items in wrong place, never inserted begin with.

the fix multiply [none] list. also, should able simplify insertion logic drastically, if iterate on elements rather indices.

p = [none] * len(flat_list)   i, y in flat_list:      p[i - 1] = y

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