尝试使用正则表达式删除行并写入新文件时出错

Question

I have a text file where each line starts with a '0', followed by a tab, and then ideally some text - however, some lines just have a '0' followed by whitespace, and I need to remove those.

EDIT: I added 'w' to the second file path, as recommended below, but now I get the following error message:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-6-ed7474583899> in <module>
      3     with open('test_02.txt', 'w', ) as append_file:
      4         for line in file:
----> 5             if not pattern(line):
      6                 append_file.write(" "+r)
      7         append_file.write("\n")

TypeError: 're.Pattern' object is not callable

when I run this code

import re

pattern = re.compile("^0\s+$")
with open('test.txt', 'w') as file:
    with open('test_02.txt') as append_file:
        for line in file:
            if not pattern(line):
                append_file.write(" "+r)
        append_file.write("\n")

but when I run it I get the following error message

FileNotFoundError                         Traceback (most recent call last)
<ipython-input-26-41d28ce0cbdf> in <module>
      3 pattern = re.compile("^0\s+$")
      4 with open('test.txt') as file:
----> 5     with open('test_02.txt') as append_file:
      6         for line in file:
      7             if not pattern(line):

FileNotFoundError: [Errno 2] No such file or directory: 'test_02.txt'

I've used the same 'with open' command before to remove stop words from the text and save them to a new file, so I'm not sure why it's generating that error now, and I haven't had any luck troubleshooting.

Answer 1

1. open the file as writeable if you plan to write to that file: with open( 'name', 'w') as fout etc.
2. you cannot call compiled re pattern pattern(line) , you have to use pattern.match(line) or something like that.
3. when creating re pattern, it's usually a good idea to use r'...' string as a pattern.
4. append_file.write(" "+r) is an error, since r is not defined anywhere.