Addendum to Strategy/ Advice for How to Best Attack this Problem?
Saran A
ahlusar.ahluwalia at gmail.com
Wed Apr 1 10:17:30 EDT 2015
On Sunday, March 29, 2015 at 8:33:43 AM UTC-4, Peter Otten wrote:
> Saran Ahluwalia wrote:
>
> > On Sunday, March 29, 2015 at 7:33:04 AM UTC-4, Saran Ahluwalia wrote:
> >> Below are the function's requirements. I am torn between using the OS
> >> module or some other quick and dirty module. In addition, my ideal
> >> assumption that this could be cross-platform. "Records" refers to
> >> contents in a file. What are some suggestions from the Pythonistas?
> >>
> >> * Monitors a folder for files that are dropped throughout the day
> >>
> >> * When a file is dropped in the folder the program should scan the file
> >>
> >> o IF all the records in the file have the same length
> >>
> >> o THEN the file should be moved to a "success" folder and a text file
> >> written indicating the total number of records processed
> >>
> >> o IF the file is empty OR the records are not all of the same length
> >>
> >> o THEN the file should be moved to a "failure" folder and a text file
> >> written indicating the cause for failure (for example: Empty file or line
> >> 100 was not the same length as the rest).
> >
> > Below are some functions that I have been playing around with. I am not
> > sure how to create a functional program from each of these constituent
> > parts. I could use decorators or simply pass a function within another
> > function.
>
> Throwing arbitrary code at a task in the hope that something sticks is not a
> good approach. You already have given a clear description of the problem, so
> start with that and try to "pythonize" it. Example:
>
> def main():
> while True:
> files_to_check = get_files_in_monitored_folder()
> for file in files_to_check:
> if is_good(file):
> move_to_success_folder(file)
> else:
> move_to_failure_folder(file)
> wait_a_minute()
>
> if __name__ == "__main__":
> main()
>
> Then write bogus implementations for the building blocks:
>
> def get_files_in_monitored_folder():
> return ["/foo/bar/ham", "/foo/bar/spam"]
>
> def is_good(file):
> return file.endswith("/ham")
>
> def move_to_failure_folder(file):
> print("failure", file)
>
> def move_to_success_folder(file):
> print("success", file)
>
> def wait_a_minute():
> raise SystemExit("bye") # we don't want to enter the loop while
> developing
>
> Now successively replace the dummy function with functions that do the right
> thing. Test them individually (preferrably using unit tests) so that when
> you have completed them all and your program does not work like it should
> you can be sure that there is a flaw in the main function.
>
> > [code]
> > import time
> > import fnmatch
> > import os
> > import shutil
> >
> >
> > #If you want to write to a file, and if it doesn't exist, do this:
>
> Hm, are these your personal notes or is it an actual script?
>
> > if not os.path.exists(filepath):
> > f = open(filepath, 'w')
> > #If you want to read a file, and if it exists, do the following:
> >
> > try:
> > f = open(filepath)
> > except IOError:
> > print 'I will be moving this to the '
> >
> >
> > #Changing a directory to "/home/newdir"
> > os.chdir("/home/newdir")
>
> Never using os.chdir() is a good habit to get into.
>
> > def move(src, dest):
> > shutil.move(src, dest)
> >
> > def fileinfo(file):
> > filename = os.path.basename(file)
> > rootdir = os.path.dirname(file)
> > lastmod = time.ctime(os.path.getmtime(file))
> > creation = time.ctime(os.path.getctime(file))
> > filesize = os.path.getsize(file)
> >
> > print "%s**\t%s\t%s\t%s\t%s" % (rootdir, filename, lastmod, creation,
> > filesize)
> >
> > searchdir = r'D:\Your\Directory\Root'
> > matches = []
> >
> > def search
>
> Everytime you post code that doesn't even compile you lose some goodwill.
> In a few lines of code meant to demonstrate a problem a typo may be
> acceptable, but for something that you probably composed in an editor you
> should take the time to run it and fix at least the syntax errors.
>
> > for root, dirnames, filenames in os.walk(searchdir):
> > ## for filename in fnmatch.filter(filenames, '*.c'):
> > for filename in filenames:
> > ## matches.append(os.path.join(root, filename))
> > ##print matches
> > fileinfo(os.path.join(root, filename))
> >
> >
> > def get_files(src_dir):
> > # traverse root directory, and list directories as dirs and files as files
> > for root, dirs, files in os.walk(src_dir):
> > path = root.split('/')
> > for file in files:
> > process(os.path.join(root, file))
> > os.remove(os.path.join(root, file))
> >
> > def del_dirs(src_dir):
> > for dirpath, _, _ in os.walk(src_dir, topdown=False): # Listing the
> > files
> > if dirpath == src_dir:
> > break
> > try:
> > os.rmdir(dirpath)
> > except OSError as ex:
> > print(ex)
> >
> >
> > def main():
> > get_files(src_dir)
> > del_dirs(src_dir)
> >
> >
> > if __name__ == "__main__":
> > main()
> >
> >
> > [/code]
@PeterOtten
Thank you for the feedback - since your last correspondence I have come up with this (my most recent commit:
https://github.com/ahlusar1989/WGProjects/blob/master/P1version2.0withassumptions_mods.py
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