Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.python > #61607

Re: adding values from a csv column and getting the mean. beginner help

Show all headers | View raw

On 2013-12-11 11:10, brian cleere wrote:
> filename = sys.argv[1]
> column = int(sys.argv[2])
> 
> for line in filename() , column ():
>     elements = line.strip().split(',')
>     values.append(int(elements[col]))

1) you need to open the file

2) you need to make use of the csv module on that file

3) you need to extract the column

Thus it would looks something like

  column = int(sys.argv[2])
  f = open(sys.argv[1], "rb")
  r = csv.reader(f)
  try:
    for row in r:
      values.append(int(row[column]))
  finally:
    f.close()

which can be obtusely written as

  values = [int(row[column]) for row in csv.reader(open(sys.argv[1], "rb"))]

though the more expanded version allows you to do better error
handling (rows with insufficient columns, non-numeric/non-integer
values in the specified column, etc).

-tkc

Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

adding values from a csv column and getting the mean. beginner help brian cleere <briancleere@gmail.com> - 2013-12-11 11:10 -0800
  Re: adding values from a csv column and getting the mean. beginner help Tim Chase <python.list@tim.thechases.com> - 2013-12-11 13:20 -0600
  Re: adding values from a csv column and getting the mean. beginner help Chris Angelico <rosuav@gmail.com> - 2013-12-12 06:22 +1100
  Re: adding values from a csv column and getting the mean. beginner help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-11 19:34 +0000
  Re: adding values from a csv column and getting the mean. beginner help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-11 19:41 +0000
  Re: adding values from a csv column and getting the mean. beginner help Chris Angelico <rosuav@gmail.com> - 2013-12-12 06:46 +1100
  Re: adding values from a csv column and getting the mean. beginner help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-11 20:00 +0000
  Re: adding values from a csv column and getting the mean. beginner help Chris Angelico <rosuav@gmail.com> - 2013-12-12 07:03 +1100
  Re: adding values from a csv column and getting the mean. beginner help Tim Chase <python.list@tim.thechases.com> - 2013-12-11 14:20 -0600
  Re: adding values from a csv column and getting the mean. beginner help Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-11 20:20 +0000
  Re: adding values from a csv column and getting the mean. beginner help Christopher Welborn <cjwelborn@live.com> - 2013-12-11 18:49 -0600
  Re: adding values from a csv column and getting the mean. beginner help "M.F." <morefool@gmail.com> - 2013-12-12 09:36 +0800

csiph-web