import os
import os.path

PATH='./file.txt'

if os.path.isfile(PATH) and os.access(PATH, os.R_OK):
    print "File exists and is readable"
else:
    print "Either file is missing or is not readable"

import os
fname = "foo.txt"
if os.path.isfile(fname):
    print "file does exist at this time"
else:
    print "no such file"

1. Try opening the file:Opening the file will always verify the existence of the file. You can make a function just like so:

   def File_Existence(filepath):
       f = open(filepath)
       return True 

   If it’s False, it will stop execution with an unhanded IOError or OSError in later versions of python. To catch the exception, you have to use a try except clause. Of course, you can always use a try except statement like so (Thanks to hsandt for making me think):

   def File_Existence(filepath):
       try:
           f = open(filepath)
       except IOError, OSError: # Note OSError is for later versions of python
           return False
   
       return True

2. Use os.path.exists(path):This will check the existence of what you specify. However, it checks for files and directories so beware about how you use it.

   import os.path
   >>> os.path.exists("this/is/a/directory")
   True
   >>> os.path.exists("this/is/a/file.txt")
   True
   >>> os.path.exists("not/a/directory")
   False

3. Use os.access(path, mode):This will check whether you have access to the file. It will check for permissions. Based on the os.py documentation, typing in os.F_OK, will check the existence of the path. However, using this will create a security hole, as someone can attack your file using the time between checking the permissions and opening the file. You should instead go directly to opening the file instead of checking its permissions. (EAFP vs LBYP). If you’re not going to open the file afterwards, and only checking its existence, then you can use this.Anyways, here:

   >>> import os
   >>> os.access("/is/a/file.txt", os.F_OK)
   True

 


Directory 

import os
print(os.path.isdir("/home/el"))
print(os.path.exists("/home/el/myfile.txt"))

os provides you with a lot of these capabilities:

import os
os.path.isdir(dir_in) #True/False: check if this is a directory
os.listdir(dir_in)    #gets you a list of all files and directories under dir_in

 

Make directory on python 

import os

dirname = 'create/me'

try:
    os.makedirs(dirname)
except OSError:
    if os.path.exists(dirname):
        # We are nearly safe
        pass
    else:
        # There was an error on creation, so make sure we know about it
        raise

#Returns true for directories, not just files
>>> print os.path.exists('/this/is/a/dir')
True

#Returns true for directories, not just files
if os.path.isfile('my_settings.dat'):
    #...
    with open('my_settings.dat') as file:
       pass  #Potential for unhandled exception
True

try:
    with open('my_settings.dat') as file:
        pass
except IOError as e:
    print "Unable to open file" #Does not exist OR no read permissions

Check If a File Exists and Then Delete It in Python

 
#!/usr/bin/python
import os
 
## get input ##
filename=raw_input("Type file name to remove: ")
 
## delete only if file exists ##
if os.path.exists(filename):
    os.remove(filename)
else:
    print("Sorry, I can not remove %s file." % filename)

A Better Option To Delete A File In Python

The following code gives an error information when it can not delete the given file name:

 
#!/usr/bin/python
import os
 
## get input ##
filename=raw_input("Type file name to remove: ")
 
## check if a file exists on disk ##
## if exists, delete it else show message on screen ##
if os.path.exists(filename):
	try:
		os.remove(filename)
	except OSError, e:
		print ("Error: %s - %s." % (e.filename,e.strerror))
else:
	print("Sorry, I can not find %s file." % filename)

Sample outputs: