calling tar commands

[tcurdts]

I think what I’m trying to do is very basic but I’m a rank beginner and I’m stuck. I’m using Python 2.4.1 on WindowsNT. I’ve installed UnxUtils, which includes the tar commands for Windows.

Immediate objective:
I have a text file containing a list of tar files, one filename per line. For now I’m just trying to loop through my text file and untar each file in the list.

Background/big picture:
Ultimately I’d like to
• Loop through the list and untar each tar file (~1700 files total),
• import some of the un-tarred components of the original tar file into an image processing program (ERDAS Imagine),
• zip the output from Imagine, and
• delete the unneeded files from the original tar.

So far, I’m able to loop through the list and print filenames. Also, the tar command is working from the command line (and batch file) but I’m missing something when I try to integrate the tar command onto python.

Here’s what I’ve got so far:

#####Loop through and print each line (works fine):

 
import fileinput
 
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
inFile = open(path + "\\tarList7.txt", 'r')
 
for line in inFile:
    print line
 
inFile.close()
 
print "Done!"
 

#####Trying to add tar component:

import fileinput
import tarfile
 
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
inFile = open(path + "\\tarList2.txt", "r")
 
line = inFile.readline()
tar = tarfile.open(line)
 
for line in inFile:
    print line
    tar.extractall()
    tar.close()
 
inFile.close()
 

Thanks in advance...

[ilikepython]

I think what I’m trying to do is very basic but I’m a rank beginner and I’m stuck. I’m using Python 2.4.1 on WindowsNT. I’ve installed UnxUtils, which includes the tar commands for Windows.

Immediate objective:
I have a text file containing a list of tar files, one filename per line. For now I’m just trying to loop through my text file and untar each file in the list.

Background/big picture:
Ultimately I’d like to
• Loop through the list and untar each tar file (~1700 files total),
• import some of the un-tarred components of the original tar file into an image processing program (ERDAS Imagine),
• zip the output from Imagine, and
• delete the unneeded files from the original tar.

So far, I’m able to loop through the list and print filenames. Also, the tar command is working from the command line (and batch file) but I’m missing something when I try to integrate the tar command onto python.

Here’s what I’ve got so far:

#####Loop through and print each line (works fine):

 
import fileinput
 
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
inFile = open(path + "\\tarList7.txt", 'r')
 
for line in inFile:
    print line
 
inFile.close()
 
print "Done!"
 

#####Trying to add tar component:

import fileinput
import tarfile
 
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
inFile = open(path + "\\tarList2.txt", "r")
 
line = inFile.readline()
tar = tarfile.open(line)
 
for line in inFile:
    print line
    tar.extractall()
    tar.close()
 
inFile.close()
 

Thanks in advance...

What's the error?

I haven't used this module at all but why are you closing the tar file in the for loop?

[ghostdog74]

I think what I’m trying to do is very basic but I’m a rank beginner and I’m stuck. I’m using Python 2.4.1 on WindowsNT. I’ve installed UnxUtils, which includes the tar commands for Windows.

Immediate objective:
I have a text file containing a list of tar files, one filename per line. For now I’m just trying to loop through my text file and untar each file in the list.

Background/big picture:
Ultimately I’d like to
• Loop through the list and untar each tar file (~1700 files total),
• import some of the un-tarred components of the original tar file into an image processing program (ERDAS Imagine),
• zip the output from Imagine, and
• delete the unneeded files from the original tar.

So far, I’m able to loop through the list and print filenames. Also, the tar command is working from the command line (and batch file) but I’m missing something when I try to integrate the tar command onto python.

Here’s what I’ve got so far:

#####Loop through and print each line (works fine):

 
import fileinput
 
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
inFile = open(path + "\\tarList7.txt", 'r')
 
for line in inFile:
    print line
 
inFile.close()
 
print "Done!"
 

#####Trying to add tar component:

import fileinput
import tarfile
 
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
inFile = open(path + "\\tarList2.txt", "r")
 
line = inFile.readline()
tar = tarfile.open(line)
 
for line in inFile:
    print line
    tar.extractall()
    tar.close()
 
inFile.close()
 

Thanks in advance...

extractall() takes in arguments...

[ilikepython]

extractall() takes in arguments...

Yea but they're optional. If a path is not given, it uses the current directory.

[ghostdog74]

Yea but they're optional. If a path is not given, it uses the current directory.

oops, my bad for misreading.

for line in open("tarlist.txt"):
    line=line.strip()
    tar = tarfile.open(line)
    for t in tar:
        tar.extract(t)
 

[tcurdts]

Sorry... meant to include the error. I included my code in my original posting to show that I've at least been trying, but I'm so green that I suspect there's a better, cleaner way to do this.

Here's the error msg (trailing newline):

Error Message:
Traceback (most recent call last):
File "C:\Python24\Li b\site-packages\python win\pywin\frame work\scriptutil s.py", line 310, in RunScript
exec codeObject in __main__.__dict __
File "C:\PythonScrip ts\MyScripts\Sc ript3.py", line 9, in ?
tar = tarfile.open(li ne)
File "C:\Python24\li b\tarfile.py", line 916, in open
return func(name, "r", fileobj)
File "C:\Python24\li b\tarfile.py", line 959, in gzopen
fileobj = file(name, mode + "b")
IOError: [Errno 2] No such file or directory: 'NZT05013031111 6199500.tar\n'

[ilikepython]

Sorry... meant to include the error. I included my code in my original posting to show that I've at least been trying, but I'm so green that I suspect there's a better, cleaner way to do this.

Here's the error msg (trailing newline):

Error Message:
Traceback (most recent call last):
File "C:\Python24\Li b\site-packages\python win\pywin\frame work\scriptutil s.py", line 310, in RunScript
exec codeObject in __main__.__dict __
File "C:\PythonScrip ts\MyScripts\Sc ript3.py", line 9, in ?
tar = tarfile.open(li ne)
File "C:\Python24\li b\tarfile.py", line 916, in open
return func(name, "r", fileobj)
File "C:\Python24\li b\tarfile.py", line 959, in gzopen
fileobj = file(name, mode + "b")
IOError: [Errno 2] No such file or directory: 'NZT05013031111 6199500.tar\n'

Try:

tar = tarfile.open(line[:-1])
 

That will remove the trailing new line.

[bartonc]

Try:

tar = tarfile.open(line[:-1])
 

That will remove the trailing new line.

As will tar = tarfile.open(line.strip())

In case there is no newline at the end.

[tcurdts]

Thanks much!! I've got the code working (untarring files contained in a txt file) when the python script is located in the same directory as the tar files.

Two more questions:
1) How do I specify different input and output directories so I can run the script from a different location and put my output (untarred files) in yet another directory?
2) Is there redundancy in lines 5 and 8?

Here's the code that's working as described above:

import fileinput
import tarfile
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
tfile = "\\tarList2.txt"
inFile = open(path + tfile)
line = inFile.readline()
 
for line in open(path + tfile):
    line = line.strip()
    print line
    tar = tarfile.open(line)
    for t in tar:
        tar.extract(t)
 

[ilikepython]

Thanks much!! I've got the code working (untarring files contained in a txt file) when the python script is located in the same directory as the tar files.

Two more questions:
1) How do I specify different input and output directories so I can run the script from a different location and put my output (untarred files) in yet another directory?
2) Is there redundancy in lines 5 and 8?

Here's the code that's working as described above:

import fileinput
import tarfile
path = r"C:\WorkSpace\LTC\MRLC_test\NZT\tmp"
tfile = "\\tarList2.txt"
inFile = open(path + tfile)
line = inFile.readline()
 
for line in open(path + tfile):
    line = line.strip()
    print line
    tar = tarfile.open(line)
    for t in tar:
        tar.extract(t)
 

You don't need to open the file every line. Also it is a good idea to use the os module for files and directories for portability:

import os, os.path
import tarfile
import fileinput
 
path = raw_input("Enter a directory: ")
tfile = raw_input("Enter the file: ")
 
for line in open(os.path.join(path, tfile)):
    line = line.strip()
    print line
    tar = tarfile.open(line)
    for t in tar:
        tar.extract(t)
 

I replaced your path with raw_input() calls, is that you need?

Also, it might be a good idea to check if the path exists so your program doesn't raise an exception.