How to iterate over files, perform operations and then rename them in Python?

Question

I have files in a directory, named as hosts_access_log_00.txt, hosts_access_log_01.txt and so on till 13. And the output for the respective files must be stored in the respective files : bytes_hosts_access_log_00.txt, bytes_hosts_access_log_01.txt and so on till 13 and they should be stored in the current directory. How do I achieve this ? In the above code I am only able to achieve this with 1 file.

with open('hosts_access_log_00.txt', 'r') as input_file:
    bytes = []
    for lines in input_file.readlines():
        words = lines.split()
        bytes.append(words[-1])

bytes = list(int(byte) for byte in bytes)
usable_bytes = []
sum = 0
for usable in bytes:
    if usable > 5000:
        usable_bytes.append(usable)
        sum += usable

print(usable_bytes, sum)
bytecount = '{}'.format(len(usable_bytes))
sum_state = '{}'.format(sum)

with open('bytes_hosts_access_log_00.txt', 'w') as output_file:
    output_file.write(bytecount +'\n'+ sum_state)

Use the [`os`](https://docs.python.org/3/library/os.html) module. Functions like `os.listdir()` are very useful... — MattDMo, Sep 24 '20 at 17:40
@MattDMo I am fairly new to Python. Do you mind helping me with the code.. — HElloWold, Sep 24 '20 at 17:42
this will help https://stackoverflow.com/questions/3964681/find-all-files-in-a-directory-with-extension-txt-in-python — deadshot, Sep 24 '20 at 17:43
1. Get the list of files that you are interested from your directory (https://stackoverflow.com/a/3207973/10451749) 2. Iterate through that list and do stuff — Pritesh Gohil, Sep 24 '20 at 17:43
@deadshot My main issue is not with finding all text files but building a custom one at the ned. — HElloWold, Sep 24 '20 at 17:44
@deadshot how do I go through performing operations and then in the end save them in file which has the corresponding number at the end — HElloWold, Sep 24 '20 at 17:49

score 0 · Answer 1 · edited Sep 24 '20 at 17:50

You have 14 files and they are named consecutively, right? I would use a simple loop and f-strings.

for filenumber in range(14):
    filenumber = str(filenumber)
    filenumber = '0' * (2 - len(filenumber)) + filenumber
    with open(f'hosts_access_log_{filenumber}.txt', 'r') as input_file:
        bytes = []
        for lines in input_file.readlines():
            words = lines.split()
            bytes.append(words[-1])

    bytes = list(int(byte) for byte in bytes)
    usable_bytes = []
    sum = 0
    for usable in bytes:
        if usable > 5000:
            usable_bytes.append(usable)
            sum += usable

    print(usable_bytes, sum)
    bytecount = '{}'.format(len(usable_bytes))
    sum_state = '{}'.format(sum)

    with open(f'bytes_hosts_access_log_{filenumber}.txt', 'w') as output_file:
        output_file.write(bytecount +'\n'+ sum_state)

Thanks for fixing the typo, @MattDMo – Kate Melnykova Sep 24 '20 at 17:51 — Kate Melnykova, Sep 24 '20 at 17:51
No prob. Things like that just jump out at me. – MattDMo Sep 24 '20 at 17:52 — MattDMo, Sep 24 '20 at 17:52

How to iterate over files, perform operations and then rename them in Python?

1 Answers1