search a word in a file using python

Question

In shell, cat filename | grep -i error would return content from the file having the string 'error' .

What is the Python equivalent of this ?

Why cannot you just open the file and read it line by line and print out the lines with `error` in it? — Anand S Kumar, Jul 09 '15 at 05:13
possible duplicate of [Grep and Python](http://stackoverflow.com/questions/1921894/grep-and-python) — dting, Jul 09 '15 at 05:14

score 2 · Answer 1 · answered Jul 09 '15 at 05:13

Open the file, iterate over all the lines and print the lines only if it contains error.

with open(file) as f:
    for line in f:
        if 'error' in line:
            print(line)

for case-insensitive match,

with open(file) as f:
    for line in f:
        if re.search(r'(?i)error', line):
            print(line)

1 Answers1