Read lines from file and split line on last delimiter in Python and save it to another file-CodePudding

I have a file named data.txt which contains names, mails and addresses separated by a colon. It looks like this:

first_name1:last_name1:[email protected]:address1
first_name2:last_name2:[email protected]:address2
first_name3:last_name3:[email protected]:address3
first_name4:last_name5:[email protected]:address4
first_name5:last_name6:[email protected]:address5
first_name6:last_name7:[email protected]:address6
first_name7:last_name8:[email protected]:address7

I would like to read only addresses and store it in separate file called addresses.txt (one address in a line). I tried such a code:

#name of file to store addresses
file_save = open("adresses.txt", 'a')

with open('data.txt', 'r') as file_to_open:
    data = file_to_open.read().rsplit(":",1)

    file_save.write(data[-1])

    print(data) #for testing only

file_to_open.close()

BUT it gives me such a result:

['first_name1:last_name1:mail1:address1\nfirst_name2:last_name2:mail2:address2\nfirst_name3:last_name3:mail3:address3\nfirst_name4:last_name5:mail4:address4\nfirst_name5:last_name6:mail5:address5\nfirst_name6:last_name7:mail6:address6\nfirst_name7:last_name8:mail7', 'address7']

What i have done wrong?

I try to make it something like this:

address1
address2
address3
...

Please help

CodePudding user response：

data = file_to_open.readlines()

for line in data:
    print(line.split(':')[-1])

CodePudding user response：

file_save = open("adresses.txt", 'a')

with open('data.txt', 'r') as file_to_open:
    data = file_to_open.read().split("\n")  # first split into lines
    addresses = []  # initialize address list
    for line in data:
        address = line.split(":")[-1]  # get last element splitted by ":"
        addresses.append(address)  # save to addresses
    file_save.write("\n".join(addresses))  # one new line between each entry

file_save.close()  # this needs to be file_save not file_to_open

CodePudding user response：

You could try using the split method on each line of data

file_save = open("adresses.txt", 'a')

with open('data.txt', 'r') as file_to_open:
    data = file_to_open.readlines();
    for address in data:
        file_save.write(address.split(":")[-1])

file_to_open.close()

CodePudding user response：

Using csv and a comprehension:

import csv 
with open('data.txt') as rf, open('address.txt', 'w') as wf:
    wf.writelines(a[-1]   '\n' for a in csv.reader(rf, delimiter=':'))

Or without csv:

with open('data.txt') as rf, open('address.txt', 'w') as wf:
    wf.writelines(a.split(':')[-1] for a in rf)