Convert WindowsPath to String

Question

redpath = os.path.realpath('.')              
thispath = os.path.realpath(redpath)        
fspec = glob.glob(redpath+'/*fits')
thispath = os.path.realpath(thispath+'/../../../..')
p = Path(thispath)
userinput = 'n'
while (userinput == 'n'):
   text_file = next(p.glob('**/*.fits'))
   print("Is this the correct file path?")
   print(text_file)
   userinput = input("y or n")

parent_dir = text_file.parent.resolve()
fspec = glob.glob(parent_dir+'/*fits')

I am getting the error

unsupported operand type(s) for +: 'WindowsPath' and 'str'

I think this is because I am trying to glob a Windows File Path when I need to glob a string. Is there a way that I can convert WindowsPath to string so that I can glob all the files into one list?

Sinuate

Instead of + try os.path.join(). https://mcmap.net/q/49720/-how-should-i-write-a-windows-path-in-a-python-string-literal – Neary

Which line of code? You have more info than we do. – Snub

try type(parent_dir), I think it is WindowsPath (not str). + operation failing due to different types. – Foliolate

Two things to consider: pathlib supports glob: clickme and also relative paths, which can be resolved like Path(...).resolve() – Catholicon

Does this answer your question? How can I convert a pathlib Path object to a string? – Corsica

Answer 1

As most other Python classes do, the WindowsPath class, from pathlib, implements a non-defaulted "dunder string" method (__str__). It turns out that the string representation returned by that method for that class is exactly the string representing the filesystem path you are looking for. Here an example:

from pathlib import Path

p = Path('E:\\x\\y\\z')
>>> WindowsPath('E:/x/y/z')

p.__str__()
>>> 'E:\\x\\y\\z'

str(p)
>>> 'E:\\x\\y\\z'

The str builtin function actually calls the "dunder string" method under the hood, so the results are exaclty the same. By the way, as you can easily guess calling directly the "dunder string" method avoids a level of indirection by resulting in faster execution time.

Here the results of the tests I've done on my laptop:

from timeit import timeit

timeit(lambda:str(p),number=10000000)
>>> 2.3293891000000713

timeit(lambda:p.__str__(),number=10000000)
>>> 1.3876856000000544

Even if calling the __str__ method may appear a bit uglier in the source code, as you saw above, it leads to faster runtimes.

Fredericafrederich

The str(variable) solved a similar problem for me whilst piping from pathLib.Path(variable) with a string variable Frankensteinian stitching operating. Thanks! – Wabash

Note that you shouldn't call special methods directly. You should always use str() / len() / ... because they check the return type (in this case it doesn't matter) – Sofiasofie

Answer 2

You are right, you need a string when you call glob.glob. In the last line of your code, parent_dir is a pathlib.Path object, which you cannot concatenate with the string '/*fits'. You need to explicitly convert parent_dir to a string by passing it to the built-in str function.

The last line of your code should thus read:

fspec = glob.glob(str(parent_dir)+'/*fits')

To illustrate further, consider this example:

>>> from pathlib import Path
>>> path = Path('C:\\')
>>> path
WindowsPath('C:/')
>>> str(path)
'C:\\'
>>>

Modulus

Pathlib supports glob: docs.python.org/3/library/pathlib.html#pathlib.Path.glob – Catholicon