Finding large files

Question

Just looking for some feedback. I designed a script to find big files that are taking up lots of space. Still a beginner, and appreciative of constructive feedback, with both the function and form/style/formatting.

#! /usr/bin/env python3
# -*- coding: utf-8 -*-
# findlargefiles.py Searches a file location and subdirectories for
# files larger than a given size.
"""
findlargefiles.py Searches a file location and subdirectories for
files larger than a given size.

Created on Sun Sep  3 20:35:12 2017

@author: toonarmycaptain
"""

import os


def searchfolder(location, filesize):
    FileNotFoundErrorsCount = 0
    filesfoundcount = 0
    print('Files larger than '+str(int(filesize))+' MB in location: '+location)
    for foldername, subfolders, filenames in os.walk(location):
            for filename in filenames:
                try:
                    actualsize = os.path.getsize(os.path.join(foldername,
                                                              filename))
                    if filesize*1024**2 <= actualsize:
                        print(foldername
                              + '\\'  # file path + \ + file name
                              + filename
                              + ' - '
                              + '{:.2f} MB'.format(actualsize/1024**2))
                        filesfoundcount += 1
                except FileNotFoundError:
                    FileNotFoundErrorsCount += 1
                    print('FileNotFoundError: '+filename)
    print('Files found: '+str(filesfoundcount))
    if FileNotFoundErrorsCount > 0:
        print('FileNotFoundErrors: '+str(FileNotFoundErrorsCount))


print('This program searches for files larger than a given size '
      'in a given location.')

while True:
    location = input("Where would you like to search? ")
    if os.path.exists(location):
        break
    else:
        print('Please enter a valid path.')
filesize = float(input('Please enter file size in MB: '))

searchfolder(location, filesize)

Answer 1

A more flexible approach would separate the printing from the finding. This allows you to use search_folder for other purposes, and cleans up the logic a bit.

More idiomatically in Python this might be formatted something like:

def search_folder(location, min_filesize):
    for folder, subfolders, filenames in os.walk(location):
        for filename in filenames:
            try:
                size_bytes = os.path.getsize(os.path.join(foldername, filename))
                if min_filesize * 1024 ** 2 <= size_bytes:
                    yield filename, size_bytes
            except FileNotFoundError:
                # maybe log error, maybe `pass`, maybe raise an exception
                # (halting further processing), maybe return an error object

if __name__ == '__main__':
    print('This program searches for ...')
    ...

    print('Files larger than %d MB in location: %s' % (filesize, location))
    for filename, size in search_folder(location, filesize):
        print(...)

• The if __name__ == '__main__' block allows you to import this script in other Python files, without triggering the interactive logic.
• search_folder now returns an iterator of (filename, size) pairs, and leaves the printing up to the function that calls it.
  • Now I can run this with no printing, purely to count files, for example.
• Standard Python style is to use underscore_case for function and variable names, and especially to start with lowercase (eg. files_not_found_count instead of FileNotFoundErrorsCount)
• Wrapping things in str() when printing is unnecessary if you use one of the various string-formatting tools (%-formatting or '{}'.format) instead of +
• I'm not sure under what conditions you would get FileNotFoundError on paths returned from os.walk, other than deleted files. If that's true in general, the most appropriate error handling may just be to silently continue.