Writing to files

[Daley, MarkX]

Here is a piece of code I wrote to write the items in a list sequentially to
a file.

Definitions:

a=some list ([1,2,3,whatever])
f=open('filename','a')

	for x in a:
		f.write(a[x])

When I run it, I get this:

	Traceback (innermost last):
 		 File "<pyshell#2>", line 1, in ?
   		 collect.collect()
  	File "C:\PROGRA~1\Python\collect.py", line 30, in collect
    		f.write(a[x])
	TypeError: sequence index must be integer

Any ideas on what is causing this?  The data in the list is columnar
information pulled from a database, but this shouldn't be the cause of the
problem because I can substitute a print statement in for the f.write
statement and it works just fine.  Any suggestions are appreciated.

Regards,

Mark Daley