在python中转置大制表符分隔的文件

Question

I am trying to transpose a huge tab delimited file with about 6000 rows and 2 million columns. The preferable approach should not involving holding the whole file in memory, which seems to be what the answer in this question does:

How to do row-to-column transposition of data in csv table?

Answer 1

One approach would be to iterate over the input file once for every column (untested code!):

with open("input") as f, open("output", "w") as g:
    try:
        for column_index in itertools.count():
            f.seek(0)
            col = [line.split("\t")[column_index] for line in f]
            g.write("\t".join(col) + "\n")
    except IndexError:
        pass

This is going to be very slow, but only keeps a single line at a time in memory.