Strategy/ Advice for How to Best Attack this Problem?
Saran A
ahlusar.ahluwalia at gmail.com
Thu Apr 2 19:43:01 EDT 2015
On Thursday, April 2, 2015 at 5:11:20 PM UTC-4, Dave Angel wrote:
> On 04/02/2015 09:06 AM, Saran A wrote:
>
> >
> > Thanks for your help on this homework assignment. I started from scratch last night. I have added some comments that will perhaps help clarify my intentions and my thought process. Thanks again.
> >
> > from __future__ import print_function
>
> I'll just randomly comment on some things I see here. You've started
> several threads, on two different forums, so it's impractical to figure
> out what's really up.
>
>
> <snip some code I'm not commenting on>
> >
> > #Helper Functions for the Success and Failure Folder Outcomes, respectively
> >
> > def file_len(filename):
>
> This is an indentation error, as you forgot to start at the left margin
>
> > with open(filename) as f:
> > for i, l in enumerate(f):
> > pass
> > return i + 1
> >
> >
> > def copy_and_move_File(src, dest):
>
> ditto
>
> > try:
> > shutil.rename(src, dest)
>
> Is there a reason you don't use the move function? rename won't work if
> the two directories aren't on the same file system.
>
> > # eg. src and dest are the same file
> > except shutil.Error as e:
> > print('Error: %s' % e)
> > # eg. source or destination doesn't exist
> > except IOError as e:
> > print('Error: %s' % e.strerror)
> >
> >
> > # Call main(), with a loop that calls # validate_files(), with a sleep after each pass. Before, my present #code was assuming all filenames come directly from the commandline. There was no actual searching #of a directory.
> >
> > # I am assuming that this is appropriate since I moved the earlier versions of the files.
> > # I let the directory name be the argument to main, and let main do a dirlist each time through the loop,
> > # and pass the corresponding list to validate_files.
> >
> >
> > path = "/some/sample/path/"
> > dirlist = os.listdir(path)
> > before = dict([(f, None) for f in dirlist)
> >
> > #####Syntax Error? before = dict([(f, None) for f in dirlist)
> > ^
> > SyntaxError: invalid syntax
>
> Look at the line in question. There's an unmatched set of brackets. Not
> that it matters, since you don't need these 2 lines for anything. See
> my comments on some other forum.
>
> >
> > def main(dirlist):
>
> bad name for a directory path variable.
>
> > while True:
> > time.sleep(10) #time between update check
>
> Somewhere inside this loop, you want to obtain a list of files in the
> specified directory. And you want to do something with that list. You
> don't have to worry about what the files were last time, because
> presumably those are gone. Unless in an unwritten part of the spec,
> you're supposed to abort if any filename is repeated over time.
>
>
> > after = dict([(f, None) for f in dirlist)
> > added = [f for f in after if not f in before]
> > if added:
> > print('Sucessfully added new file - ready to validate')
> > ####add return statement here to pass to validate_files
> > if __name__ == "__main__":
> > main()
>
> You'll need an argument to call main()
>
> >
> >
> > #check for record time and record length - logic to be written to either pass to Failure or Success folder respectively
> >
> > def validate_files():
>
> Where are all the parameters to this function?
>
> > creation = time.ctime(os.path.getctime(added))
> > lastmod = time.ctime(os.path.getmtime(added))
> >
> >
> >
> > #Potential Additions/Substitutions - what are the implications/consequences for this
> >
> > def move_to_failure_folder_and_return_error_file():
> > os.mkdir('Failure')
> > copy_and_move_File(filename, 'Failure')
> > initialize_logger('rootdir/Failure')
> > logging.error("Either this file is empty or there are no lines")
> >
> >
> > def move_to_success_folder_and_read(f):
> > os.mkdir('Success')
> > copy_and_move_File(filename, 'Success')
> > print("Success", f)
> > return file_len()
> >
> > #This simply checks the file information by name------> is this needed anymore?
> >
> > def fileinfo(file):
> > filename = os.path.basename(f)
> > rootdir = os.path.dirname(f)
> > filesize = os.path.getsize(f)
> > return filename, rootdir, filesize
> >
> > if __name__ == '__main__':
> > import sys
> > validate_files(sys.argv[1:])
> >
> > # -- end of file
> >
>
>
> --
> DaveA
@DaveA
I debugged and rewrote everything. Here is the full version. Feel free to tear this apart. The homework assignment is not due until tomorrow, so I am currently also experimenting with pyinotify as well. I do have questions regarding how to make this function compatible with the ProcessEvent Class. I will create another post for this.
What would you advise in regards to renaming the inaptly named dirlist?
# # # Without data to examine here, I can only guess based on this requirement's language that
# # fixed records are in the input. If so, here's a slight revision to the helper functions that I wrote earlier which
# # takes the function fileinfo as a starting point and demonstrates calling a function from within a function.
# I tested this little sample on a small set of files created with MD5 checksums. I wrote the Python in such a way as it
# would work with Python 2.x or 3.x (note the __future__ at the top).
# # # There are so many wonderful ways of failure, so, from a development standpoint, I would probably spend a bit
# # more time trying to determine which failure(s) I would want to report to the user, and how (perhaps creating my own Exceptions)
# # # The only other comments I would make are about safe-file handling.
# # # #1: Question: After a user has created a file that has failed (in
# # # processing),can the user create a file with the same name?
# # # If so, then you will probably want to look at some sort
# # # of file-naming strategy to avoid overwriting evidence of
# # # earlier failures.
# # # File naming is a tricky thing. I referenced the tempfile module [1] and the Maildir naming scheme to see two different
# # types of solutions to the problem of choosing a unique filename.
## I am assuming that all of my files are going to be specified in unicode
## Utilized Spyder's Scientific Computing IDE to debug, check for indentation errors and test function suite
from __future__ import print_function
import os.path
import time
import logging
def initialize_logger(output_dir):
logger = logging.getLogger()
logger.setLevel(logging.DEBUG)
# create console handler and set level to info
handler = logging.StreamHandler()
handler.setLevel(logging.INFO)
formatter = logging.Formatter("%(levelname)s - %(message)s")
handler.setFormatter(formatter)
logger.addHandler(handler)
# create error file handler and set level to error
handler = logging.FileHandler(os.path.join(output_dir, "error.log"),"w", encoding=None, delay="true")
handler.setLevel(logging.ERROR)
formatter = logging.Formatter("%(levelname)s - %(message)s")
handler.setFormatter(formatter)
logger.addHandler(handler)
# create debug file handler and set level to debug
handler = logging.FileHandler(os.path.join(output_dir, "all.log"),"w")
handler.setLevel(logging.DEBUG)
formatter = logging.Formatter("%(levelname)s - %(message)s")
handler.setFormatter(formatter)
logger.addHandler(handler)
#Returns filename, rootdir and filesize
def fileinfo(f):
filename = os.path.basename(f)
rootdir = os.path.dirname(f)
filesize = os.path.getsize(f)
return filename, rootdir, filesize
#returns length of file
def file_len(f):
with open(f) as f:
for i, l in enumerate(f):
pass
return i + 1
#attempts to copy file and move file to it's directory
def copy_and_move_file(src, dest):
try:
os.rename(src, dest)
# eg. src and dest are the same file
except IOError as e:
print('Error: %s' % e.strerror)
path = "."
dirlist = os.listdir(path)
def main(dirlist):
before = dict([(f, 0) for f in dirlist])
while True:
time.sleep(1) #time between update check
after = dict([(f, None) for f in dirlist])
added = [f for f in after if not f in before]
if added:
f = ''.join(added)
print('Sucessfully added %s file - ready to validate') %()
return validate_files(f)
else:
return move_to_failure_folder_and_return_error_file(f)
def validate_files(f):
creation = time.ctime(os.path.getctime(f))
lastmod = time.ctime(os.path.getmtime(f))
if creation == lastmod and file_len(f) > 0:
return move_to_success_folder_and_read(f)
if file_len < 0 and creation != lastmod:
return move_to_success_folder_and_read(f)
else:
return move_to_failure_folder_and_return_error_file(f)
#Potential Additions/Substitutions
def move_to_failure_folder_and_return_error_file():
filename, rootdir, lastmod, creation, filesize = fileinfo(file)
os.mkdir('Failure')
copy_and_move_file( 'Failure')
initialize_logger('rootdir/Failure')
logging.error("Either this file is empty or there are no lines")
def move_to_success_folder_and_read():
filename, rootdir, lastmod, creation, filesize = fileinfo(file)
os.mkdir('Success')
copy_and_move_file(rootdir, 'Success') #file name
print("Success", file)
return file_len(file)
if __name__ == '__main__':
main(dirlist)
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