Merging log data in python

I would personally recommend using bash. Something like,

cat u_ex15* >> all_logs

But in python you can simply use the following:

import glob
all_log_filename = 'all_logs'
log_files = glob.glob('u_ex15*')
for filename in log_files:
    with open(filename) as reader:
        with open(all_log_filename, 'a') as writer:
             writer.write(reader.read())

NOTE: This is the simplest case where your log files aren't that large. If your log files are large, you may want to iterate over each line or chunks so that you don't run into memory issues. The simplest thing you could do is something like:

for filename in log_files:
    with open(filename) as reader:
        with open(all_log_filename, 'a') as writer:
            for line in reader:
                writer.write(line)