1

Lets say I have the two lists:

 test_names = [['timothy', 'tim'],["clara"],["jerry", "jer", "j-dog"],]   
 test_numbers = ['123','234', '345',]

I want to save them to a file, like this

123 ; timothy ; tim ;

234 ; clara ;

345 ; jerry ; jer ; j-dog ;

and then somehow return this file into the original lists above?

TobbeTrollkarl
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    Does this answer your question? [Writing a list to a file with Python, with newlines](https://stackoverflow.com/questions/899103/writing-a-list-to-a-file-with-python-with-newlines). Also see [here](https://stackoverflow.com/questions/4529815/saving-an-object-data-persistence); you can create `A=test_names, test_numbers`, and use pickle to write/read A. – dermen Oct 11 '22 at 15:22

2 Answers2

0

I think something like this:

res = {}
for key in test_keys:
    for value in test_values:
        res[value] = key
        test_values.remove(value)
        break

with open("myfile.txt", 'w') as f: 
for key, value in res.items(): 
    f.write('%s;%s;\n' % (key, value))

Will result in something like this.

123;['timothy', 'tim'];

234;['clara'];

345;["jerry", "jer", "j-dog"];

TobbeTrollkarl
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0

Your question seems to contains two. It is better to focus on one, but don't worry, i'll anwser both

TL; DR

Merge two list

list_A = ['abc', 'def', 'hij']   
list_B = ['123','234', '345']   
list_AB = []
for i in range(len(list_A)):
    list_AB.append([list_A[i], list_B[i]])
# output : [['abc', '123'], ['def', '234'], ['hij', '345']]

Save to a file

f = open("output.txt", "w")
f.write(str(list_AB))
f.close()

Explainations

In the TL;DR I provided a simple, general solution, but i'll give here a more detailled solution for your specific case

Merge two list

We loop trought all the elements of our lists :

for i in range(len(test_names)):
    combined_list = test_names[i]
    combined_list.insert(0, test_numbers[i])
    list_AB.append(combined_list)

Note : i will go from 0 (included) to len(list_A) (excluded), but if the length of list_B is different from list_A, we will have issues. This example should be improved if such cases are possibles.

Save to file

First opening the file link

f = open("output.txt", 'w') # 'w' for write (remove old content), we can use 'a' to append at the end of old content

Don't forget to always close your file after editing it.

f.close() # Else other program can't access the file (appear as being in use by Python)

In-between, we will write all our content to our file. We will use a forloop to iterate over all our elements inside list_AB

for element in list_AB:
    f.write(str(element) + ' ;\n')
# output :
# ['123', 'timothy', 'tim'] ;
# ['234', 'clara'] ;
# ['345', 'jerry', 'jer', 'j-dog'] ;

That is not exactly what we want. List are displayed as ["element1", "element2", ...], but we want a prettier output. We can use .join() :

e.g. 'something'.join(list_AB)

That will concat all element of the list, each separeted by a string (here the string "something")

for element in list_AB:
    f.write(' ; '.join(element) + ' ;\n')
# output :
# 123 ; timothy ; tim;
# 234 ; clara;
# 345 ; jerry ; jer ; j-dog;

Perfect :)

(don't forget to close your file)

Portevent
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