lists and files question

[hokiegal99]

This code:

import os, re, string
setpath = raw_input("Enter the path: ")
for root, dirs, files in os.walk(setpath):
id = re.compile('Microsoft Excel Worksheet')
fname = files
# print fname
content = open(fname[1],'rb')

Produces this error:

IOError: Error[2] No such file or directory 'Name of File'

The strange thing is that it correctly identifies the file that it says
doesn't exist. Could someone explain why this is?

Also, is "files" a nested list? It looks like one, but I'm not entirely
sure as I'm still relatively new to Python. Thanks!

 

[Mark Day]

This code:

import os, re, string
setpath = raw_input("Enter the path: ")
for root, dirs, files in os.walk(setpath):
id = re.compile('Microsoft Excel Worksheet')
fname = files
# print fname
content = open(fname[1],'rb')

Produces this error:

IOError: Error[2] No such file or directory 'Name of File'

The strange thing is that it correctly identifies the file that it says
doesn't exist. Could someone explain why this is?

The problem is that file doesn't exist in the current working
directory; it's in another directory (stored in "root" in your code).

Try this:
content = open(os.path.join(root,fname[1]), 'rb')

Also, is "files" a nested list? It looks like one, but I'm not entirely
sure as I'm still relatively new to Python. Thanks!

It is a list of strings. Each string is the name of one of the files
in the directory (whose path is in "root" above).

-Mark

 

[Sean 'Shaleh' Perry]

This code:

import os, re, string
setpath = raw_input("Enter the path: ")
for root, dirs, files in os.walk(setpath):
id = re.compile('Microsoft Excel Worksheet')
fname = files
# print fname
content = open(fname[1],'rb')

Produces this error:

IOError: Error[2] No such file or directory 'Name of File'

if you replace your logic with some prints you will quickly see the problem.

What happens is os.walk() passes filenames without their path. You need to
use os.path.join() to get the full name back.

 

[hokiegal99]

"print fname" prints out the list of files in "setpath" w/o problem. How
does it do that if os.walk doesn't give it the path to the files?

Here's some output from "print fname":

['index.txt', 'CELL-MINUTES.xls', '.nautilus-metafile.xml']
['2000 Schedule.xls', '2001 State.pdf', '2001.pdf', 'A Little More Like
Bill.doc', 'AARP.doc', "Accounting's of Dad's Est.xls",
'Amortization_Table.xls', 'huey letter.doc', 'utt-R&D.pdf', 'utt.pdf',
'rest.xls', 'Debts and Assets.xls', 'First Accounting - Estate.xls',
'Friends.doc', "Grace's.doc", 'Home Address.doc', 'Ins.doc',
'Insurance.doc', 'Interro.doc', 'Marshall.doc', 'NBB home loan.doc',
'Position Description.doc', "andy's", "Andy's Travel Voucher.xls",
"Andy's Travel.xls", 'Rebuttal.doc', 'Refinance.doc', 'TaxReturn 2.pdf',
'TaxReturn 3.pdf', 'TaxReturn 4.pdf', 'TaxReturn 5.pdf',
'TaxReturn.pdf', 'The Casey Song.doc', "Touch of the Hand.xls", 'Workout
Sheet.xls', 'application.pdf', 'budsum.pdf']

When I add os.path.join like this:

setpath = raw_input("Enter the path: ")
for root, dirs, files in os.walk(setpath):
id = re.compile('Microsoft Excel Worksheet')
fname = files
print fname
content = open(os.path.join(root,fname[0]),'rb')

I get a "IndexError: list index out of range" error.

This is a Linux 2.4 computer running Python 2.3b2... if that matters.

Thanks!

This code:

import os, re, string
setpath = raw_input("Enter the path: ")
for root, dirs, files in os.walk(setpath):
id = re.compile('Microsoft Excel Worksheet')
fname = files
# print fname
content = open(fname[1],'rb')

Produces this error:

IOError: Error[2] No such file or directory 'Name of File'

if you replace your logic with some prints you will quickly see the problem.

What happens is os.walk() passes filenames without their path. You need to
use os.path.join() to get the full name back.

 

[hokieghal99]

Thanks to everyone for the feedback on this. I've learned a lot from you
guys.

Others have already answered your question - I just want to point out
a few of other things

import os, re, string
setpath = raw_input("Enter the path: ")
for root, dirs, files in os.walk(setpath):
id = re.compile('Microsoft Excel Worksheet')

1) id is a built in function; you may not want to override it with
your variable name
135313208

2) The reason to use re.compile is for efficiency. There is no need
to call it inside the loop, since you're just recompiling the same
regex over and over again. Instead, compile the regex outside the
loop

rgx = re.compile('[A-Z]+')
for some_text in some_list:

... m = rgx.match(some_text)

3) If you want to match 'Microsoft Excel Worksheet', you don't need
regular expressions since this is a string literal. You will
probably be better off just using the string find method, as in

s.find('Microsoft Excel Worksheet')

4) You may want to look at the path module, which provides a nice
interface for walking over files:
http://www.jorendorff.com/articles/python/path/
... print f.read().find('Microsoft Excel Worksheet')

Cheers,
John Hunter