Jumping around an input file (random access)
File Handling example from a Well House Consultants training course
More on File Handling [link]
Source code: fff Module: Y110
"""This example Python program shows how a file can
be checked to see if it has grown since the previous
time the program was read, and if it *has* grown how
the newly added data can be read"""
from os.path import *
"""See how much data was handled last time. If the file
is no longer that it was then, exit the program"""
fh = open("owfar","r")
what = int(fh.readline())
where = (os.stat("pcoder"))
if where <= what:
print "no change"
"""Open the incoming data file, seek the the newly
added data, and handle that newly added data ..."""
say = ""
fh = open("pcoder","r")
for line in fh.readlines():
parts = line.strip().split("^")
say += "CONFIG ="+parts+ " -- "
say += "CATEGORY ="+parts+ " == "
say += "PRIORITY ="+parts+ " == "
say += "DESC ="+parts+ " == "
"""In this example, we're passing the newly added data
through to an operating system command (i.e. another
process) that we've started from within our Python program"
"""finally, note the current length of the incoming file
so that we know whether it's been extended next time we
run this code"""
Learn about this subject
This module and example are covered on the following public courses:
* Learning to program in Python
* Python Programming
Also available on on site courses for larger groups
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