python ignore first line with io.open

Question

I have this piece of code:

with io.open('csus.csv',mode='r',encoding='latin1') as csus:
  for line in csus:

And I need to ignore the first (header)line. Of course I can work with a virgin boolean, check it's value during the run of the for loop, when False digest the line and set it to False otherwise. But I was hoping to read the first line from the file(handle?) and continue with the for loop

csus.readline()

does not have the expected effect, is it possible and what should I use?

As as a side question should I close the csus file? I don't think this was done in the example I copied it from and I wonder wether this with .. as .. statement already incorporates the close()?

_"`csus.readline()` does not have the expected effect"_ Are you _sure_? It works for me. — Aran-Fey, Apr 03 '18 at 18:42
Consider looking into the [csv](https://docs.python.org/3/library/csv.html) module to do this for you. It's builtin to Python, so you don't have to install anything extra — Ben, Apr 03 '18 at 19:00

score 2 · Accepted Answer · answered Apr 03 '18 at 18:46

2

You can do this with:

with io.open('csus.csv',mode='r',encoding='latin1') as csus:
    next(csus)
    for line in csus:
        # do something

The with statement takes care of closing the file for you.

answered Apr 03 '18 at 18:46

Jacques Gaudin

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This is the only one that doesn't run some sort of branch for each line of code – Ben Apr 03 '18 at 18:59

score 0 · Answer 2 · answered Apr 03 '18 at 18:46

0

Try this:

enumerate and skip the first line

import io
with io.open('csus.csv',mode='r') as csus:
  for i, row in enumerate(csus):
      if(i==0):
          pass
      else:
        print(str(i) + " " + row)

answered Apr 03 '18 at 18:46

Morse

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`'{} {}'.format(i, row)` is much sexier (read pythonic). – Mick_ Apr 03 '18 at 18:56

Mick_ · Answer 3 · 2018-04-03T18:54:43.997

0

You can easily achieve it with below code:

with open('any.txt', 'r') as f:
    for i, line in enumerate(f):
        if i > 0:
            print(line) # Change to line.strip() to get rid of new line after everyline

edited Apr 03 '18 at 18:54

answered Apr 03 '18 at 18:49

Mick_

131
9

python ignore first line with io.open

3 Answers3