topic Re: Python Novice Question - Get a list of files in a directory with particular exten in Geoprocessing Questions

Python Novice Question - Get a list of files in a directory with particular extension

SheriNorton — Fri, 20 Aug 2010 14:32:46 GMT

I need to generate a list of all files in a directory with a *.MDB extension (personal geodatabases) in a Python script. Should I first split the path and filenames:

dirname = "C:\Arcwork"
(filepath, filename) = os.path.split(dirname)

and then somehow split the filename into name and extension (how?!), or vice versa?

Re: Python Novice Question - Get a list of files in a directory with particular exten

ChrisMathers — Sat, 11 Dec 2021 20:24:06 GMT

I would:

dirlist=os.listdir(r"C:\Arcwork")
mdblist=[]
for item in dirlist:
    if item[-3:] in ['MDB','mdb']
        mdblist.append(item)

its kind of wordy and a bit brute-force but it works 😛

Re: Python Novice Question - Get a list of files in a directory with particular exten

SheriNorton — Fri, 20 Aug 2010 16:25:53 GMT

Thanks - tried this but validation returns a syntax error.

Re: Python Novice Question - Get a list of files in a directory with particular exten

BBicking1 — Fri, 20 Aug 2010 17:16:00 GMT

Thanks - tried this but validation returns a syntax error.

Hi...

MBldr's Iterate Files [ArcGIS10] with File Extension set to .mdb will do what you want. Connect the Collect Values ModelOnly Tool to the iterator's output to get the list. Note though at this time the list is not export-able or save-able.

Barbara Bicking
GeoprocessingTeam

Re: Python Novice Question - Get a list of files in a directory with particular exten

SheriNorton — Fri, 20 Aug 2010 18:46:21 GMT

I've tweaked the code:

import os

dirlist=os.listdir("c:\\Arcwork")
mdblist=[]
for item in dirlist:
    if item.endswith("mdb"):
        print item
        mdblist.append[item]

print mdblist
_____________________________
But I get this error: do I need to import another module to use the "Append'?
Traceback (most recent call last):
File "C:\Python26\ArcGIS10.0\Lib\site-packages\Pythonwin\pywin\framework\scriptutils.py", line 325, in RunScript
    exec codeObject in __main__.__dict__
File "C:\Arcwork\GetMasterMDBList.py", line 8, in <module>
    mdblist.append[item]
TypeError: 'builtin_function_or_method' object is unsubscriptable

Re: Python Novice Question - Get a list of files in a directory with particular exten

DanPatterson_Retired — Sat, 11 Dec 2021 20:24:09 GMT

append uses round brackets

>>> a_list = []
>>> for i in [1,2,3,4]:
...  a_list.append(i)
...  
>>> print a_list
[1, 2, 3, 4]
>>>

Re: Python Novice Question - Get a list of files in a directory with particular exten

KarlOrmer — Sat, 11 Dec 2021 20:24:12 GMT

You want to call a method. You call objects by using round brackets.

clm42's snippet misses a `:` at the end of line 4.

Please note that Python is case-sensitive. Your attempt will fail if a file is - for whatever reason - called .MDB, .mDb or .mDB.

>>> a = 'test.MDB'
>>> a.endswith('mdb')
False

Therefore you need to "convert" your item variable to lower-case before testing for 'mdb'

>>> a = 'test.MDB'
>>> a.lower()
'test.mdb'
>>> a.lower().endswith('mdb')
True

This adds up to:

dirlist=os.listdir("c:\\Arcwork")
mdblist=[]
for item in dirlist:
    if item.lower().endswith("mdb"):
        print item
        mdblist.append(item)

print mdblist

Re: Python Novice Question - Get a list of files in a directory with particular exten

SheriNorton — Fri, 20 Aug 2010 19:55:01 GMT

Presto!!! Thanks so much to you all. :o) I promise to be on the "giving" side down the road... Have a terrific weekend.

-Sheri

Re: Python Novice Question - Get a list of files in a directory with particular exten

Luke_Pinner — Sat, 11 Dec 2021 20:24:15 GMT

Better late than never 🙂

import glob
for mdb in glob.glob('c:\\Arcwork\\*.mdb'):
    print mdb

The above snippet will return *.mdb and *.MDB (and *.MdB etc.) on case-insensitive filesystems, such as Windows.
For maximum portability, use something like:

for mdb in glob.glob(os.path.join(searchdir,*.[mM][dD][bB]')):
    print mdb

Re: Python Novice Question - Get a list of files in a directory with particular exten

SheriNorton — Tue, 24 Aug 2010 12:00:35 GMT

Neat - thanks Luke! Sounds like this should work for Windows as well as Unix platform? I'll give a shot this morning. It's good to see there's usually more than one way of "skinning the cat".

Re: Python Novice Question - Get a list of files in a directory with particular exten

Luke_Pinner — Wed, 25 Aug 2010 00:21:35 GMT

Both code snippets will work on Windows and unix/linux, but the top one will only return *.mdb (not *.MDB/*.MdB/etc...) on unix/linux as those OSs have case-sensitive file systems (generally speaking, as there are case-insensitive types of filesystems for linux and you can enable case-sensivity for certain Windows filesystems).

Re: Python Novice Question - Get a list of files in a directory with particular exten

TedCronin — Wed, 25 Aug 2010 00:39:13 GMT

There is also a new List at ArcGIS 10 called ListFiles, arcpy.ListFiles ("*.mdb").

Re: Python Novice Question - Get a list of files in a directory with particular exten

DanielSmith — Thu, 21 Oct 2010 20:26:37 GMT

i like using:

for root, dirs, files in os.walk(r'your root directory'):

that way you can access directories and files independently.

Re: Python Novice Question - Get a list of files in a directory with particular exten

NiklasNorrthon — Thu, 21 Oct 2010 21:43:04 GMT

Here are two more ways to do this:

import os
personal_gdbs = [file for file in os.listdir('c:/Arcwork' if file.lower().endswith('.mdb')]

or

import arcpy
arcpy.env.workspace = 'c:/Arcwork'
personal_gdbs = arcpy.ListWorkspaces('*.mdb')

Re: Python Novice Question - Get a list of files in a directory with particular exten

HugoAhlenius — Fri, 29 Oct 2010 10:26:21 GMT

import os
personal_gdbs = [file for file in os.listdir('c:/Arcwork') if file.lower().endswith('.mdb')]

To me, this looks like cleanest!
(I corrected a paranthesis in the snippet)

Re: Python Novice Question - Get a list of files in a directory with particular exten

TedCronin — Fri, 29 Oct 2010 22:01:29 GMT

This is a great thread.