WriteDataFile.py

#WriteDataFile.py
#Python3.4
#Chris Clarke
#04.10.2015

import sys

filename = input( "Enter name of file to create: ")

try:
    fh = open( filename, "r")
    fh.close()
except IOError:
    pass
else:
    overwrite = input( "File exists.  Overwrite (y/n) ? ")
    if overwrite.lower() in ("y", "yes"):
        pass
    else:
        print( "Overwrite cancelled." )
        sys.exit()

try:
    fdata = open( filename, "w" ) # open text file to write to
    x = 0
    while x>=0:
        x = int( input( "Enter integer number (-1 to quit) : " ) )
        if x<0:
            break
        fdata.write( str(x)+'\n' )
except IOError:
    print( "Error: can\'t write to file" )
else:
    print( "Written content in the file successfully" )
    fdata.close()