Import modules in lambda functions (Python)

2010-06-16T20:13:15-07:00

Python recipe 577269 by roopeshv .

I am not sure how many know that we can import modules inside lambda functions. So I am writing this to make the feature standout.

Instead of having the following function, which joins the paths

import os
relative_to_current = lambda *x: os.path.join(os.path.dirname(__file__), *x)

# current directory is suppose /home/user/ (on linux) OR C:\Users (on Windows)
>>> relative_to_current('Desktop')
'/home/user/Desktop' # on linux
'C:\\Users\\Desktop'

Here is same thing without having to import os in the module.

dealing with directory paths with ~ (Python)

2010-06-16T23:17:20-07:00

Python recipe 577270 by roopeshv (directory, expanding, paths). Revision 2.

Dealing with directory paths which start with ~ which are passed as paramaters, to os module functions.

Here is what I think python doesn't do for me:

>>> import os
# suppose my home = curdir = /home/rv
>>> os.path.abspath('.') 
'/home/rv'

Now if I want to go to folder /home/rv/test if there is no folder by name /home/rv/~/test/

# This is what happens by default.
>>> os.path.abspath('~/test')
'/home/rv/~/test'

>>> os.chdir('/home/rv/some/dir')
# doesn't matter if the resulting path exists or not.
>>> os.path.abspath('~/test')
'home/rv/some/dir/~/test'

This would be more sensible I guess:

# if /home/rv/~/test doesn't exist
>>> os.path.abspath('~/test')
'/home/rv/test'

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Import modules in lambda functions (Python)

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