"""Path utility to:
* split a path entirely,
* join it,
* return true commonprefix on paths.
>>> path = os.getcwd()
>>> join(split(path)) == path
True
>>> p1, p2, p3 = (os.path.join(*'abc'), os.path.join(*'abd'),
... os.path.join(*'ab'))
>>> commonprefix(p1, p2, p3) == p3
True
"""
import os
import os.path
from itertools import takewhile
def isplit(path):
"Generator splitting a path"
dirname, basename = os.path.split(path)
if path == dirname:
# stop recursivity
yield path
elif dirname:
# continue recursivity
for i in isplit(dirname):
yield i
if basename:
# return tail
yield basename
def split(path):
"""Return the folder list of the given path
>>> split(os.path.join('a', 'b'))
['a', 'b']
"""
return list(isplit(path))
def join(iterable):
"""Join iterable's items as a path string
>>> join(('a', 'b')) == os.path.join('a', 'b')
True
"""
return os.path.join(*iterable)
def _equal_elem(iterable):
"""Return True if all elements of the container are equal.
>>> _equal_elem((0,1)), _equal_elem((0,0))
(False, True)
"""
first = _first(iterable)
return all(x == first for x in iterable)
def _first(iterable):
"Return first element of an iterable"
return next(iter(iterable))
def commonprefix(*paths):
"""Return the common prefix path of the given paths
>>> commonprefix(os.path.join('a', 'c'), os.path.join('a', 'b'))
'a'
"""
tuples = zip(*map(isplit, paths))
return join(map(_first, takewhile(_equal_elem, tuples)))
if __name__ == '__main__':
import doctest
doctest.testmod()
