Using os.sep in Python?

Question

What is os.sep and when should i use os.sep while scripting for arcgis ?

For example in below code i don't understand why should i use os.sep .

import arcpy
from arcpy import env
import os

# Set the workspace for the ListFeatureClass function
#
env.workspace = "c:/base"

# Use the ListFeatureClasses function to return a list of 
#  all shapefiles.
#
fcList = arcpy.ListFeatureClasses()

# Copy shapefiles to a file geodatabase
#
for fc in fcList:
  arcpy.Copy_management(fc, "d:/base/output.gdb" + os.sep + fc.rstrip(".shp"))

Answer 1

Just use os.path.join(), noting the caveat for Windows at http://docs.python.org/dev/library/os.path.html. It takes care of the os.sep for you and makes your code more portable (not that ArcPy is portable, but in general).

for fc in fcList:
    arcpy.Copy_management(
        fc, os.path.join("d:/base/output.gdb", fc.rstrip(".shp")))

Answer 2

try this...

In your favourite python environment type:

import os
print os.sep

Your output will be '\'or '/' depending on the operating system you're using.

@artwork21's answer is more complete ;) and beat me to the punch line!