11Answers
  • 8
name

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name Punditsdkoslkdosdkoskdo

How to get the parent dir location

this code is get the templates/blog1/page.html in b.py:

path = os.path.join(os.path.dirname(__file__), os.path.join('templates', 'blog1/page.html'))

but i want to get the parent dir location:

aParent
   |--a
   |  |---b.py
   |      |---templates
   |              |--------blog1
   |                         |-------page.html
   |--templates
          |--------blog1
                     |-------page.html

and how to get the aParent location

thanks

updated:

this is right:

dirname=os.path.dirname
path = os.path.join(dirname(dirname(__file__)), os.path.join('templates', 'blog1/page.html'))

or

path = os.path.abspath(os.path.join(os.path.dirname(__file__),".."))
      • 2
    • os.path.join('templates', 'blog1/page.html') looks strange to me. You are mixing things up. Either os.path.join('templates', 'blog1', 'page.html') or 'templates/blog1/page.html'. And much easier would be os.path.abspath(os.path.join('templates', 'blog1', 'page.html')) then
      • 2
    • @zjm: no, you don't get that page. It's not some blackbox that you could just use to get the template file. It performs a series of trivial small steps, and if you could understand them, you wouldn't have this question.

You can apply dirname repeatedly to climb higher: dirname(dirname(file)). This can only go as far as the root package, however. If this is a problem, use os.path.abspath: dirname(dirname(abspath(file))).

  • 169
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    • I know the OP knows about dirname. It isn't obvious to everyone that applying dirname to a directory yields the parent directory.
      • 1
    • @Sridhar: That depends on your perspective; I consider a path ending in / as not representing the leaf directory entry itself, but its contents, which is why, e.g., mv xxx yyy/ fails if yyy isn't a preexisting directory. In any case, even if we take your point as a given, it is irrelevant in the context of my answer. Neither file nor the result of dirname will ever end in a /.
      • 2
    • Minor correction: dirname may return '/', which clearly ends in a /. That is the only exception, AFAIK.

os.path.abspath doesn't validate anything, so if we're already appending strings to __file__ there's no need to bother with dirname or joining or any of that. Just treat __file__ as a directory and start climbing:

# climb to __file__'s parent's parent:
os.path.abspath(__file__ + "/../../")

That's far less convoluted than os.path.abspath(os.path.join(os.path.dirname(__file__),"..")) and about as manageable as dirname(dirname(__file__)). Climbing more than two levels starts to get ridiculous.

But, since we know how many levels to climb, we could clean this up with a simple little function:

uppath = lambda _path, n: os.sep.join(_path.split(os.sep)[:-n])

# __file__ = "/aParent/templates/blog1/page.html"
>>> uppath(__file__, 1)
'/aParent/templates/blog1'
>>> uppath(__file__, 2)
'/aParent/templates'
>>> uppath(__file__, 3)
'/aParent'
  • 55
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    • This is nice, but it would also be cool if the standard library added a convenience function that accomplished this...don't want to come to SO every time I need this func

Use relative path with the pathlib module in Python 3.4+:

from pathlib import Path

Path(__file__).parent

You can use multiple calls to parent to go further in the path:

Path(__file__).parent.parent

As an alternative to specifying parent twice, you can use:

Path(__file__).parents[1]
  • 40
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os.path.dirname(os.path.abspath(__file__))

Should give you the path to a.

But if b.py is the file that is currently executed, then you can achieve the same by just doing

os.path.abspath(os.path.join('templates', 'blog1', 'page.html'))
  • 12
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Here is another relatively simple solution that:

  • does not use dirname() (which does not work as expected on one level arguments like "file.txt" or relative parents like "..")
  • does not use abspath() (avoiding any assumptions about the current working directory) but instead preserves the relative character of paths

it just uses normpath and join:

def parent(p):
    return os.path.normpath(os.path.join(p, os.path.pardir))

# Example:
for p in ['foo', 'foo/bar/baz', 'with/trailing/slash/', 
        'dir/file.txt', '../up/', '/abs/path']:
    print parent(p)

Result:

.
foo/bar
with/trailing
dir
..
/abs
  • 1
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I think use this is better:

os.path.realpath(__file__).rsplit('/', X)[0]


In [1]: __file__ = "/aParent/templates/blog1/page.html"

In [2]: os.path.realpath(__file__).rsplit('/', 3)[0]
Out[3]: '/aParent'

In [4]: __file__ = "/aParent/templates/blog1/page.html"

In [5]: os.path.realpath(__file__).rsplit('/', 1)[0]
Out[6]: '/aParent/templates/blog1'

In [7]: os.path.realpath(__file__).rsplit('/', 2)[0]
Out[8]: '/aParent/templates'

In [9]: os.path.realpath(__file__).rsplit('/', 3)[0]
Out[10]: '/aParent'
  • 0
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