tailhead
Python tail is a simple implementation of GNU tail and head.
It provides 3 main functions that can be performed on any file-like object that supports seek() and tell().
-
tail- read lines from the end of a file -
head- read lines from the top of a file -
follow- read lines as a file grows
It also comes with pytail, a command line version offering the same functionality as GNU tail. This can be particularly useful on Windows systems that have no tail equivalent.
Installation
Install with pip or easy_install.
pip install tailhead
Examples
import tailhead
f = open('test.txt', 'w')
for i in range(11):
f.write('Line %d\\n' % (i + 1))
f.close()
Tail
# Get the last 3 lines of the file
tailhead.tail(open('test.txt', 'rb'), 3)
# [b'Line 9', b'Line 10', b'Line 11']
Head
# Get the first 3 lines of the file
tailhead.head(open('test.txt', 'rb'), 3)
# [b'Line 1', b'Line 2', b'Line 3']
Follow
# Follow the file as it grows and handle file rotation if it occurs
import time
for line in tailhead.follow_path('test.txt'):
if line is not None:
print(line)
else:
time.sleep(1)
Running Tests
Tailer currently only has doctests.
Run tests with nose:
nosetests --with-doctest tailhead
Run tests with doctest:
python -m doctest -v tailhead/__init__.py
