Find the maximum line length in a given TSV colum
This code can be recast into something that will be more efficient if all you are doing is scanning the file for the length of the longest line:

longest_item = None
for row in csv_reader:
    current_item_length = len(row[column])
    if current_item_length &gt; longest_item:
        longest_item = current_item_length


Can be replaced with this:

longest_item = max((len(r[column]) for r in csv_reader))


So, what did we build here?  Working from the inside out:

len(r[column])


will return the length of the column in r. While

(len(r[column]) for r in csv_reader)


produces a generator which can return all of the lengths of column returned by csv_reader. And finally:

max((len(r[column]) for r in csv_reader))


returns the largest value of all of the column lengths.