I'm wondering how to slice only the USERNAMES from a text file, I know the basic slicing but with the exact index only like dates and time.

The file looks like this

username: kara_v password: 123456 dept: accounting vlan: 5
username: carla_s password: 654321 dept: accounting vlan: 5
username: mary_j password: 345645 dept: accounting vlan: 5
username: leny_k  password: 568890 dept: accounting vlan: 5
username: raul_t  password: abscdf dept: production1 vlan: 6
username: paul_s  password: hgytt dept: production1 vlan: 6
username: steph_j  password: gfrrss dept: production1 vlan: 6
username: sally_g  password: appookk dept: production1 vlan: 6
username: maan_h  password: 123rfg dept: branch1 vlan: 11
username: ricky_m password: 678yuh dept: branch1 vlan: 11
username: zola_b  password: gghh12 dept: branch1 vlan: 11
username: jeremy_n password: fgh347 dept: branch1 vlan: 11

CodePudding user response：

If you want to open the file, scan all the lines for the patter username: <some_string> this little regex can do that:

note: usernames.txt below is the same as the lines you've posted above.

import re


with open('usernames.txt') as f:
    lines = f.read()
    usernames = re.findall(r'username: (.*?)[\s]', lines)
    print(usernames)

1. re.findall finds all occurrences of the string match username:
2. (.*?) matches any character except a newline
3. [\s] escapes on any whitespace character
4. This prints a list of all the usernames

['kara_v', 'carla_s', 'mary_j', 'leny_k', 'raul_t', 'paul_s', 'steph_j', 'sally_g', 'maan_h', 'ricky_m', 'zola_b', 'jeremy_n']

CodePudding user response：

Would this work? considering text file name is info.txt

modified based on comment

def mysplit(x):
    return x.split()[1]
    

with open('info.txt') as f: 
    lines = f.readlines()
    users = list(map(mysplit,lines))
    print(users)

CodePudding user response：

One more approach with sed (not thoroughly tested)

sed 's/ password.*$//;s/username: //' inputfile