Work with a list of list and make some comparisons Python

I don't know how compare 2 different lists of list and write what I need:
I have a list of list. I need to check 3 things.
First if the item[1], item[2] of este_mes item are in the list resto and add the complete item to changes.
Second if the item[1], item[2] of este_mes item are not in the resto, add to news and for the item[1], item[2] of resto item are not este_mes, add to lost

item[1], item[2]

este_mes

item

resto

item

changes

item[1], item[2]

este_mes

item

resto

news

the item[1], item[2]

resto

item

este_mes

lost

este_mes = [
['1', 'A', 'a', '300'],
['1', 'B', 'b', '30'],
['1', 'C', 'c', '100'],
['1', 'D', 'd', '4500']]

resto = [
['2', 'A', 'a', '3'],
['2', 'B', 'b', '302'],
['2', 'X', 'x', '98'],
['2', 'Z', 'z', '276'],
['3', 'A', 'a', '54'],
['3', 'B', 'b', '65'],
['3', 'F', 'f', '76'],
['3', 'Y', 'y', '99']]

# I need something like this but I don't know how can I do it!

changes =
news =
lost =

for item in este_mes:
if item[1] and item[2] are in some item of resto:
changes.append(item_resto)
if item[1] and item[2] are not in some item of resto:
news.append(item)
for item in resto:
if item[1] and item[2] are not in item of este_mes:
lost.append(item_resto)


the answers should be:

news = [['1', 'C', 'c', '100'],
['1', 'D', 'd', '4500']]
lost = [['2', 'X', 'x', '98'],
['2', 'Z', 'z', '276'],
['3', 'F', 'f', '76'],
['3', 'Y', 'y', '99']]
changes = [['2', 'A', 'a', '3'],
['2', 'B', 'b', '302'],
['3', 'A', 'a', '54'],
['3', 'B', 'b', '65']]


This is the answer:

este_mes =
resto =
changes =

for item in este_mes:
for rest in resto:
if (item[1] == rest[1] and item[2] == rest[2]):
rest = [rest[0]] + [item[1]] + [item[2]] + ([float(item[3]) - float(rest[3])])
changes.append(rest)
resto.remove(rest)


news

3 Answers
3

I have commented the code so hopefully you can follow the logic.

#initialise our lists
news =
changes =
lost =
#iterate over each list in `este_mes`
for l in este_mes:
#matches marks whether we have matched in `resto`
matched = False
for ll in resto:
if l[1] == ll[1] and l[2] == ll[2]:
#we matched, so append list from `resto` to changes
changes.append(ll)
matched = True
#if there were no matches, append the `este_mes` list to `news`
if not matched:
news.append(l)

#iterate over lists in `resto` to look for ones to add to `lost`
for l in resto:
#check to see if there are any matches in `este_mes`
for ll in este_mes:
if l[1] == ll[1] and l[2] == ll[2]:
break
else:
#this `else` clause is run if there was no `break` -
#indicates that no matches were found so add to `lost`.
lost.append(l)


which outputs the correct lists:

>>> news
[['1', 'C', 'c', '100'], ['1', 'D', 'd', '4500']]
>>> lost
[['2', 'X', 'x', '98'], ['2', 'Z', 'z', '276'], ['3', 'F', 'f', '76'], ['3', 'Y', 'y', '99']]
>>> changes
[['2', 'A', 'a', '3'], ['3', 'A', 'a', '54'], ['2', 'B', 'b', '302'], ['3', 'B', 'b', '65']]


Use the any operator to see whether there is any occurrence of a particular condition within a list. In this case, I compare two-letter sequences for each new list.

any

For each of these, make sure to grab the item from the proper list (este_mes or resto). That list has to be the outer for in the list comprehension + iterable combination. That's why the first of these has este in the outer part, while the other two have rest in the outer part.

for

este

rest

news = [este for este in este_mes
if not any((rest[1], rest[2]) == (este[1], este[2])
for rest in resto)]

changes = [rest for rest in resto
if any((rest[1], rest[2]) == (este[1], este[2])
for este in este_mes)]

lost = [rest for rest in resto
if not any((rest[1], rest[2]) == (este[1], este[2])
for este in este_mes)]

print(news)
print(lost)
print(changes)


Output:

[['1', 'C', 'c', '100'], ['1', 'D', 'd', '4500']]
[['2', 'A', 'a', '3'], ['2', 'B', 'b', '302'], ['3', 'A', 'a', '54'], ['3', 'B', 'b', '65']]
[['2', 'X', 'x', '98'], ['2', 'Z', 'z', '276'], ['3', 'F', 'f', '76'], ['3', 'Y', 'y', '99']]


any(rest[1] == este[1] and rest[2] == este[2] for rest in resto)

(rest[1], rest[2]) == (este[1], este[2])

'A'+'bc'=='Ab'+'c'

As far as I can tell, your actual question is simply "how do I check whether something is in an item of resto?"

resto

Here's a nice way:

def in_item(items, value):
return any(value in item for item in items)

# For example
in_item([[1, 3], [5]], 1)
Out: True
in_item([[1, 3], [5]], 2)
Out: False


Then you can do if in_item(resto, item[1]) and in_item(resto, item[2]): and so on.

if in_item(resto, item[1]) and in_item(resto, item[2]):

resto

Required, but never shown

Required, but never shown

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