How to check if file exists in Eiffel

import os, csv

# store file attributes for easy modifications
# format is 'filename': (hashcolumn, filepathNum)
files = {
        'A.csv': (7, 5),
        'B.csv': (15, 5),
        'C.csv': (1, 0),
        }

class NoFilesFound(Exception):
    "No .csv files were found to clean up"

def chkifexists(somefiles):
    # load all three at once, but only yield them if filename
    # is found
    filesfound = False
    for fname, (hashcolumn, filepathNum) in somefiles.items():
        if os.path.isfile(fname):
            filesfound = True
            yield fname, hashcolumn, filepathNum
    if not filesfound:
        raise NoFilesFound

def removedupes(infile, outfile, hashcolumn, filepathNum):
    # this is now a single-run function
    r1 = file(infile, 'rb')
    r2 = csv.reader(r1)
    w1 = file(outfile, 'wb')
    w2 = csv.writer(w1)
    hashes = set()
    for row in r2:
        if row[hashcolumn] =="": 
            w2.writerow(row)       
            hashes.add(row[hashcolumn])  
        if row[hashcolumn] not in hashes:
            w2.writerow(row)
            hashes.add(row[hashcolumn])
    w1.close()
    r1.close()


def bakcount(origfile1, origfile2):
    '''This function creates a .bak file of the original and does a row count
    to determine the number of rows removed'''
    os.rename(origfile1, origfile1+".bak")
    count1 = len(open(origfile1+".bak").readlines())
    #print count1

    os.rename(origfile2, origfile1)
    count2 = len(open(origfile1).readlines())
    #print count2

    print str(count1 - count2) + " duplicate rows removed from " \
        + str(origfile1) +"!"


def CleanAndPrettify():
    print "Removing duplicate rows from input files..."
    try:
        for fname, hashcolumn, filepathNum in chkifexists(files):
            removedupes(
                   fname,
                   os.path.splitext(fname)[0] + "2.csv",
                   hashcolumn,
                   filepathNum,
                   )
            bakcount (fname, os.path.splitext(fname)[0] + "2.csv")
    except NoFilesFound:
        print "no files to clean up"

CleanAndPrettify()

def chkifexists(somefiles):
    # load all three at once, but only yield them if filename
    # is found
    for fname, (hashcolumn, filepathNum) in somefiles.items():
        if os.path.isfile(fname):
            filesfound = True
            yield fname, hashcolumn, filepathNum

def CleanAndPrettify():
    print "Removing duplicate rows from input files..."
    found_files = list(chkifexists(files))
    if not found_files:
        print "no files to clean up"
    else:
        for fname, hashcolumn, filepathNum in found_files:
            removedupes(...)
            bakcount(...)

FileWriter userData = new FileWriter(fileName);
if (userData.exists())

File userDataFile = new File(fileName);
if (userDataFile.exists())

FileWriter userData = new FileWriter(userDataFile);
userData.write(user + " ");
userData.write(ps);
userData.close();

System.out.println(new File(fileName).getAbsolutePath());

' Exctract the directory path
Dim xmlSaveDir=System.IO.Path.GetDirectoryName(xmlSaveLocation)

' Create directory if it doesn't exit
If (Not System.IO.Directory.Exists(xmlSaveDir)) Then
    System.IO.Directory.CreateDirectory(xmlSaveDir)
End If

' now, use a file stream for the XmlWriter, this will create or overwrite the file if it exists
Using fs As New FileStream(xmlSaveLocation, FileMode.OpenOrCreate, FileAccess.Write)
    Using writer As XmlWriter = XmlWriter.Create(fs)
        ' use the writer...
        ' and, when ready, flush and close the XmlWriter
        writer.Flush()
        writer.Close()
    End Using
    ' flush and close the file stream
    fs.Flush()
    fs.Close()
End Using

l_foo := foo
if not attached l_foo then
    create l_foo
    foo := l_foo
end
l_foo.bark