ska_file

API docs

Ska file utilities

class ska_file.File.TempDir(*args, **kwargs)

Create a temporary directory that gets automatically removed. Any object initialization parameters are passed through to tempfile.mkdtemp.

>>> import ska_file
>>> tmpdir = ska_file.TempDir(dir='.')
>>> tmpdir.name
'./tmpcCH_l-'
>>> del tmpdir

ska_file.File.chdir(dirname=None)

Context manager to run block within dirname directory. The current directory is restored even if the block raises an exception.

>>> with chdir(dirname):
>>>     print "Directory within chdir() context:", os.getcwd()
>>> print "Directory after chdir() context:", os.getcwd()

Parameters

dirname – Directory name

ska_file.File.get_globfiles(fileglob, minfiles=1, maxfiles=1)

Get file(s) matching fileglob. If the number of matching files is less than minfiles or more than maxfiles then an exception is raised.

Parameters

• fileglob – Input file glob

• minfiles – Minimum matching files (None => no minimum)

• maxfiles – Maximum matching files (None => no maximum)

ska_file.File.make_local_copy(infile, outfile=None, copy=False, linkabs=False, clobber=True)

Make a local copy of or link to infile, gunzipping if necessary.

Parameters

• infile – Input file name

• outfile – Output file name (default: infile basename)

• copy – Always copy instead of linking when possible

• linkabs – Create link to absolute path instead of relative

• clobber – Clobber existing file

Return type

Output file name

>>> import ska_file
>>> import random, tempfile
>>> a = os.linesep.join([str(random.random()) for i in range(100)])
>>> tmpfile = tempfile.mkstemp()[1]
>>> open(tmpfile, 'w').write(a)
>>> stat = subprocess.Popen(['gzip', '--stdout', tmpfile], stdout=open(tmpfile+'.gz','w')).communicate()
>>> tmplocal = ska_file.make_local_copy(tmpfile, clobber=True)
>>> a == open(tmplocal).read()
True
>>> tmplocal = ska_file.make_local_copy(tmpfile+'.gz', clobber=True)
>>> a == open(tmplocal).read()
True
>>> os.unlink(tmpfile)
>>> os.unlink(tmplocal)

ska_file.File.relpath(path, cwd=None)

Find relative path from current directory to path.

Example usage:

>>> from ska_file import relpath
>>> relpath('/a/b/hello/there', cwd='/a/b/c/d')
'../../hello/there'
>>> relpath('/a/b/c/d/e/hello/there', cwd='/a/b/c/d')
'e/hello/there'

>>> # Special case - don't go up to root and back
>>> relpath('/x/y/hello/there', cwd='/a/b/c/d')
'/x/y/hello/there'

Parameters

• path – Destination path

• cwd – Current directory (default: os.getcwd() )

Return type

Relative path

ska_file.File.reversed_lines(filename)

Generate the lines of filename in reverse order.

Adapted from: http://stackoverflow.com/questions/260273/most-efficient-way-to-search-the-last-x-lines-of-a-file-in-python/

Parameters

filename – file name

Returns

generator of reversed file lines