Scanning log file for instability
Additional Python Facilities example from a Well House Consultants training course
More on Additional Python Facilities [link]
Source code: eo2.py Module: Y115
""" This program reads in a data file with a series of lines of the
14-AUG-2007 16:16:04.00, 2.277, -649.20,0.00, 5792.00,237.77, 99.623
and reports on changes from one log line to the next of +- 1% in any
of the data fields after the timestamp. """
# Method to evaluate whether of not a big change occurred
c = float(a) / float(b)
if c > 1.0: c = 1.0 / c
if c < 0.99: return 1
# Define the pattern against which to match the data lines.
# Note the use of string functions to meaningfully build up
# a complex regular expression
date = r"\d\d-...-\d\d\d\d"
time = r"(\d\d):(\d\d):(\d\d.\d\d)"
whitespace = r"\s+"
floater = r"(-?\d+\.\d+)"
wholeline = date + whitespace + time + "," + whitespace + \
floater + "," + whitespace + floater + "," + floater + \
"," + whitespace + floater + "," + floater + "," + \
whitespace + floater
dataline = re.compile(wholeline)
fh = open("eo_monitor.txt","r")
# Grab in all valid data lines and reject short lines, headers, etc
datapool = 
for line in fh.readlines():
ihave = dataline.findall(line)
# Look for major changes in each column in turn
for probcol in range(3,9):
problems = 0
for row in range(1,len(datapool)):
ouch = bigchange(datapool[row][probcol],datapool[row-1][probcol])
problems += 1
print "Problems on column",probcol,"=",problems
# Also a good idea to report total data line count!
print "That's from",len(datapool),"rows"
Learn about this subject
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* Learning to program in Python
* Python Programming
* Intermediate Python
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