Question

Basically i have to dump a series of temperature readings, into a text file. This is a space delimited list of elements, where each row represents something (i don’t know, and it just gets forced into a fortran model, shudder). I am more or less handling it from our groups side, which is extracting those temperature readings and dumping them into a text file.

Basically a quick example is i have a list like this(but with alot more elements):

temperature_readings = [ [1.343, 348.222, 484844.3333], [12349.000002, -2.43333]]

In the past we just dumped this into a file, unfortunately there is some people who have this irritating knack of wanting to look directly at the text file, and picking out certain columns and changing some things (for testing.. i don’t really know..). But they always complain about the columns not lining up properly, they pretty much the above list to be printed like this:

    1.343     348.222     484844.333
12349.000002   -2.433333

So those wonderful decimals line up. Is there an easy way to do this?

Answer 1

you can right-pad like this:

str = '%-10f' % val

to left pad:

set = '%10f' % val

or in combination pad and set the precision to 4 decimal places:

str = '%-10.4f' % val

:

import sys
rows = [[1.343, 348.222, 484844.3333], [12349.000002, -2.43333]]
for row in rows:
  for val in row:
    sys.stdout.write('%20f' % val)
  sys.stdout.write("\n")

        1.343000          348.222000       484844.333300
    12349.000002           -2.433330