Use python to list directory as tab-separated values

dir.py

"""
List directory as tab-separated values
 * Written, annotated, and hastily bug-checked by Jeff Brand (@deltafactory)
 * Inspired by Rudy Trujillo, https://plus.google.com/u/0/+RudyTrujillo/posts/7yWsPXVvKmt
"""

# Import os and sys packages since we'll be using them. (Look for sys.* and os.* below.)
# More info: https://docs.python.org/3/reference/import.html
import os, sys

# Check for command-line arguments array to see if a path was specified, e.g: dir.py /home/deltafactory
# The first arg (index 0) is the script name. Index 1 is the only one we care about, if present.
if len( sys.argv ) > 1:
	path = sys.argv[1]

# Otherwise, we want the current working directory.
else:
	path = '.'

# Print tab-separated header. Note sep="\t" puts tabs between the elements.
# More info: https://docs.python.org/3/library/functions.html#print
print( 'Filename', 'Type', 'Size', 'Modified Time', sep="\t" )

# os.listdir() provides a list (array) of filenames from the specified path.
# The for-loop stores each filename into f to be used in the block within.
for f in os.listdir(path):

	# Combine the starting path and filename into a "full" path to the file.
	# os.path.join() takes care of OS-specifics
	# More info: https://docs.python.org/2/library/os.path.html#os.path.join
	filepath = os.path.join( path, f )

	# Ternary operator used to set value for "Type" column: dir or file
	fod = 'dir' if os.path.isdir( filepath ) else 'file'

	# There is probably a better way to detect whether we can stat() a file without exception handling.
	# Exception handling is a big topic..
	# More info: https://docs.python.org/3.4/tutorial/errors.html
	try:
		# This throws an error with insufficient permission.
		# When it works, it gets information about the file/dir including size and date.
		# More info: https://docs.python.org/3/library/os.html#os.stat
		fs = os.stat(filepath)
		fsinfo = [fs.st_size, fs.st_mtime]
	except:
		# If an exception occurred in the "try" block above, enter some blanks.
		# Otherwise, the previous file's data would remain and be printed below.
		fsinfo = ['', '']

	# Print columns: Filename, Type, Size, Modified Time - using tab character as separator
	print( f, fod, fsinfo[0], fsinfo[1], sep="\t")

# Fin.

Great! It ran first time now to go and dissect what it is doing. Thank you so very much.

Wanted to take a minute to thank you for the detailed comments you added to your code it was clear and concise. You went beyond what most would have done. Again thank you for your help understanding some of the rudimentary aspects of coding in python.