Python: how to run a command while using a defined variable?

Question

I'm a beginner with Python and I'm trying to list the contents of a directory which is defined as a variable but to no avail.

This is the code:

#!/usr/bin/python
import os

location = "/home/itaig/testdir"
command = os.system('ls -l')," location"

My aim is to count the number of files in the location and print the number.

How can it be achieved?

Edit #1:

In bash I'd do ls -l $location | wc -l , what would be the equivalent in Python?

In any case, I've looked at the links from the comments but wasn't able to get it to work... can you please show me an example?

Thanks

Look at this: stackoverflow.com/questions/5533700/python-string-formatting — mguijarr
– mguijarr, Commented Jul 15, 2015 at 8:32
Your command seems odd: It should read os.system("ls -l " + location). But for listing a directory you can use the glob module, which is a bit easier to handle than calling a system command. — Falko
– Falko, Commented Jul 15, 2015 at 8:34
os.system('ls -l {0}'.format(location)) - unix os.system('dir -l {0}'.format(location)) - windows Although it may not be relevant for you, using commands will make this platform specific. — Bill Kidd
– Bill Kidd, Commented Jul 15, 2015 at 9:15

Bill Kidd · Accepted Answer · 2015-07-15 09:18:40Z

0

You can use os.listdir. This is platform independent as the os module will handle the low level work

print len(os.listdir(location))

edited Jul 15, 2015 at 9:18

answered Jul 15, 2015 at 8:57

Bill Kidd

1,20813 silver badges13 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

mguijarr · Accepted Answer · 2015-07-15 08:53:31Z

-1

You can use the good old os.popen function:

p = os.popen('ls -l %s' % location)
nb_lines = 0
while p.readline():
  nb_lines += 1

answered Jul 15, 2015 at 8:53

mguijarr

8,0306 gold badges50 silver badges77 bronze badges

1 Comment

mguijarr Over a year ago

why downvoting? It answers the question and provides and example of string formatting at the same time, and it shows how to read output from a command too

Collectives™ on Stack Overflow

Python: how to run a command while using a defined variable?

2 Answers 2

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related