[Tutor] Fwd: Logical error?

[C Smith]

The first loop tests for the last element of fullPath to have today's date.
The second loop tests the first element in fullPath, if it is not today,
you will end up running sys.exit() when you hit the else clause in second
loop.


On Fri, May 2, 2014 at 6:38 PM, C Smith <illusiontechniques at gmail.com>wrote:

> The first loop tests for the last element of fullPath to have today's
> date. The second loop tests the first element in fullPath, if it is not
> today, you will end up running sys.exit() when you hit the else clause in
> second loop.
>
>
> On Fri, May 2, 2014 at 6:19 PM, Bob Williams <linux at barrowhillfarm.org.uk>wrote:
>
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>>
>> Hi,
>>
>> I'm fairly new to coding and python. My system is linux (openSUSE
>> 13.1). I've written the following code to examine a log file, and
>> extract strings from certain lines if two conditions are met, namely
>> that the file has been modified today, and the line contains the
>> string 'recv'.
>>
>> - ---Code---
>> #!/usr/bin/python
>>
>> import sys
>> import datetime
>> import codecs
>> import subprocess
>>
>> # Format date as YYYY/MM/DD
>> today = (datetime.datetime.now()).strftime('%Y/%m/%d')
>>
>> fullPath = []   # declare (initially empty) lists
>> truncPath = []
>>
>> with codecs.open('/var/log/rsyncd.log', 'r') as rsyncd_log:
>>     for line in rsyncd_log.readlines():
>>         fullPath += [line.decode('utf-8', 'ignore').strip()]
>>     if fullPath[-1][0:10] == today:
>>         print("\n   Rsyncd.log has been modified in the last 24 hours...")
>>     else:
>>         print("\n   No recent rsync activity. Nothing to do.\n")
>>         sys.exit()
>>
>> # Search for lines starting with today's date and containing 'recv'
>> # Strip everything up to and including 'recv' and following last '/'
>> path separator
>> for i in range(0, len(fullPath)):
>>     if fullPath[i][0:10] == today and 'recv' in fullPath[i]:
>>         print("got there")
>>         begin = fullPath[i].find('recv ')
>>         end = fullPath[i].rfind('/')
>>         fullPath[i] = fullPath[i][begin+5:end]
>>         truncPath.append(fullPath[i])
>>         print("   ...and the following new albums have been added:\n")
>>     else:
>>         print("   ...but no new music has been downloaded.\n")
>>         sys.exit()
>>
>> - ---Code---
>>
>> The file rsyncd.log typically contains lines such as (sorry about the
>> wrapping):
>>
>> 2014/05/02 19:43:14 [20282]
>> host109-145-nnn-xxx.range109-145.btcentralplus.com recv Logical
>> Progression Level 3 (1998) Intense/17 Words 2 B Heard Collective -
>> Sonic Weapon.flac 72912051 72946196
>>
>> I would expect the script to output a list of artist and album names,
>> eg Logical Progression Level 3 (1998) Intense. IOW what is between the
>> string 'recv' and the trailing '/'. What it actually produces is:
>>
>> :~> python ~/bin/newstuff.py
>>
>>    Rsyncd.log has been modified in the last 24 hours...
>>    ...but no new music has been downloaded.
>>
>> This suggests that the first 'if' clause (matching the first 10
>> characters of the last line) is satisfied, but the second one isn't,
>> as the flow jumps to the second 'else' clause.
>>
>> As the script runs without complaint, this is presumably a logical
>> error rather than a syntax error, but I cannot see where I've gone wrong.
>>
>> Bob
>> - --
>> Bob Williams
>> System:  Linux 3.11.10-7-desktop
>> Distro:  openSUSE 13.1 (x86_64) with KDE Development Platform: 4.13.0
>> Uptime:  06:00am up 11:26, 4 users, load average: 0.00, 0.02, 0.05
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>> Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/
>>
>> iEYEARECAAYFAlNkGewACgkQ0Sr7eZJrmU57YwCgg91pxyQbFMSe+TqHkEjMuzQ6
>> 03MAnRQ50up6v+kYE+Hf/jK6yOqQw4Ma
>> =+w0s
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