Python "list out of the range"

There are some problems with your code:

See:

i = 0
d = []

while(i < len(dados1)):
    # O [:-1] retira o \n do final
    d2 = dados2[i][:-1]
    d1 = dados1[i][:-1]
    d.append("{} {}\n".format(d2, d1))
    i=i+1

arquivo3.writelines(d)

If you prefer a more pythonic solution:

with open("bandaIZ_coluna5_dados_não_saturados.txt", "r") as file:
    dados1 = [i[:-1] for i in file.readlines()]

with open("bandaIZ_coluna13_dados_não_saturados.txt", "r") as file:
    dados2 = [i[:-1] for i in file.readlines()]

# Nome do arquivo está estranho
with open("bandaIZ_colunas13&5", "w") as file:
    file.writelines(["{} {}\n".format(a, b) for a, b in zip(dados2, dados1)])

With with , we do not have to worry about closing the file. For each one, we read the content and store the value of each line, excluding the last character, referring to \n . This is done through a list compression:

dados = [i[:-1] for i in file.readlines()]

At the end, write the concatenation of the values in the third file. The concatenation is done through list compression and the zip function, native to Python .

If the input files are:

File 1

a
b
c
d

File 2

e
f
g
h

The final file will be:

e a
f b
g c
h d

As you yourself have stated, d is a list, but you never put anything in it. However, within your loop, you try to access the elements d [i], so an error occurs.

What you probably want to do is:

d.append([d2,d1])

In addition, the write argument is str, not list. To put the contents of your list on file, you will probably want to do:

for item in d:
    arquivo3.write(str(item[0]) + str(item[1]))

In Python, a list is represented as a sequence of objects separated by commas and inside brackets [], so an empty list, for example, can be represented by brackets with no content. Listing 1 shows some possibilities for creating this type of object.

>>> lista = [] 
>>> lista
[]
>>> lista = ['O carro','peixe',123,111]
>>> lista
['O carro', 'peixe', 123, 111]
>>> nova_lista = ['pedra',lista]
>>> nova_lista
['pedra', ['O carro', 'peixe', 123, 111]]

• Lines 1 to 3: Declaration of a list with no element and its impression, which shows only the brackets, indicating that the list is empty;
• Lines 4 to 6: Assigning two strings and two integers to the list variable and its subsequent printing;
• Lines 7 to 9: Creating and printing the variable new_list, which is initialized with the string 'stone', and another list.

The possibilities of declaring and assigning values to a list are many, and the choice of one or the other depends on the context and application.

List Operators

The Python language has several methods and operators to assist in the manipulation of lists. The first and most basic is the operator accessing your items from the indexes. To understand it, it is important to understand how the data is stored in this structure, which is illustrated in Figure 1.

Thelistrepresentedinthisfigureiscomposedoffourelementswhoseindicesvaryfromzerotothree.Forexample,thefirstobject,atindex0,isthestring'Thecar'.Keepinginmindthisinternalorganization,wecanaccesseachelementusingthesyntaxlist[index],asshowninListing2.

Seemoreinthis python course .