Best way to accommodate unknown number of variables?

[bowlofred]

Usually you wouldn't bother to pre-initialize, especially if you didn't know the exact number beforehand. Instead, just process as necessary and append or add to a collection.

results = []
with open("mydata") as f:
    for line in f:
        # process each line as necessary.
        hostname = line.split()[0]
        results.append[hostname]

# all the processed hostnames are now in the results list
...