def parse(filename): """Parses the given file line by line while following it""" try: fd = open(filename) except IOError: print "Could not read file:", filename lines = follow(fd) for line in lines: parsed = parse_line(line) if parsed == None: continue yield parsed
def parse(filename): """Parses the given file line by line while following it""" try: fd = open(filename) except IOError: print "Could not read file:", filename lines = follow(fd) for line in lines: parsed = parse_line(line) if parsed == None: continue yield parsed
from tail import follow lines = follow(open('www/access-log')) for i, line in enumerate(lines): print(i, 'line: ', line, end='') if i == 4: lines.close()
import time import threading from tail import follow shutdown = threading.Event() lines = follow(open('www/access-log'), shutdown) def sleep_and_close(s): time.sleep(s) print('Closing it down') shutdown.set() threading.Thread(target=sleep_and_close, args=(10, )).start() for line in lines: print(line, end='')
print(item) yield item class storelast: def __init__(self, source): self.source = source def __next__(self): item = self.source.__next__() self.last = item return item def __iter__(self): return self if __name__ == '__main__': gen_sqrt = generate(math.sqrt) for x in trace(gen_sqrt(range(10))): pass print('--------------------') lines = storelast(follow(open('www/access-log'))) log = apache_log(lines) for r in log: print(r) print(lines.last)
# One of the most pwerful applications of generators is # setting up processing pipelines. # input sequence -> generator -> generator -> for x in a import tail def grep(pattern, lines): for line in lines: if pattern in lines: yield line logfile = open("access-log") loglines = tail.follow(logfile) pylines = grep("python", loglines) for line in pylines: print(line)
def feed_queue(log_q): lines = open('www/access-log') lines = follow(lines) log = apache_log(lines) sendto_queue(log, log_q)
from tail import follow from parser import apache_log from sendto import sendto lines = open('www/access-log') lines = follow(lines) log = apache_log(lines) sendto(log, ("", 15000))
#!/usr/bin/python # when a new query appears into log file, blink the little green led (#25) import RPi.GPIO as GPIO import os import time import tail # Some varaibles logFile = "/opt/neo4j/logs/query.log" blinkTime = 0.1 # Set GPIO mode that match the board number GPIO.setmode(GPIO.BCM) # Setup to on the little red led GPIO.setup(25, GPIO.OUT, initial=GPIO.LOW) # What we do when a new query appers ? try: for data in tail.follow(logFile): GPIO.output(25, GPIO.HIGH) time.sleep(0.1) GPIO.output(25,GPIO.LOW) except KeyboardInterrupt: GPIO.cleanup() exit(0)