python从包含NA的文本中删除行

Question

I have data at http://people.stern.nyu.edu/ja1517/data/marketing.data , which I've saved as marketing.data.txt

I want to remove lines that contain NA. I wrote a 6 line python script, but it isn't working.

Can anyone point out my mistake?

import re
f = open('marketing.data.txt')
g = open('marketing_complete.txt', 'w')
for line in f:
    if re.search('NA', line) is None:
        g.write(line)

I know this hasn't worked because I tried the following at the command line.

grep 'NA' marketing_complete.txt | wc -l

which returns 3... :(

Answer 1

You don't need re to do this:

f = open('marketing.data.txt')
g = open('marketing_complete.txt', 'w')
for line in f:
    if 'NA' not in line:
        g.write(line)

It is good practice to open files with context managers:

with open('marketing.data.txt') as f:
   with open('marketing_complete.txt', 'w') as g:
       for line in f:
           if 'NA' not in line:
               g.write(line)

Answer 2

您可以grep-

grep -v NA marketing.data.txt > marketing_complete.txt

Answer 3

If you are already grepping, just do:

grep -v NA marketing.data.txt > marketing_complete.txt

The '-v' option inverts the search so only lines that don't match are printed.

Answer 4

对于您的if语句，请尝试

if 'NA' not in line: