CODEWITHSUNDEEP
python
Masoud Rahimi
Masoud Rahimi

Reputation: 6051

Absolute path of string that contains special characters

In my code, I get a path from the database that may contain special escaping characters that I need to convert them to a real path name. I'm using python 3.7 on Windows. Suppose this path: C:\Files\2c2b2541\00025\test.x

IMPORTANT: the path is not a fixed value in the code and it is an output of executing a Stored Procedure from pyodbc. When I try to convert it to an absolute path I get this error:

ValueError: _getfullpathname: embedded null character in path

I also tried to replace "\" with "/" but with no luck.

import os

# path = cursor.execute(query, "some_input").fetchone()[0]
path = 'C:\Files\2c2b2541\00025\test.x'

print(os.path.abspath(path))

Upvotes: 1

Views: 1589

Answers (4)

Blckknght
Blckknght

Reputation: 104852

Judging by your comments on the other answers, it sounds like the data is already corrupted in the database you're using. That is, you have a literal null byte stored there, and perhaps other bogus bytes (like \2 perhaps turning into \x02). So you probably need two fixes.

First, you should fix whatever code is putting values into the database, so it won't put bogus data in any more. You haven't described how the data gets into the database, so I we can't give you much guidance on how to do this. But most programming languages (and DB libraries) have tools to prevent escape sequences from being evaluated in strings where they're not wanted.

Once you've stopped new bad data from getting added, you can work on fixing the values that are already in the database. It probably shouldn't be too hard to write a query that will replace \0 null bytes with \\0 (or whatever the appropriate escape sequence is for your DB). You may want to look for special characters like newlines (\n) and unprintable characters (like \x02) as well.

I'd only try to fix this issue on the output end if you don't have any control of the database at all.

Upvotes: 1

hygull
hygull

Reputation: 8730

I think the below is the right way to solve your problem.

>>> def get_fixed_path(path):
...     path = repr(path)
...     path = path.replace("\\", "\\\\")
...     path = path.replace("\\x", "\\\\0")
...     path = os.path.abspath(path3).split("'")[1]
...     return path
...
>>>
>>> path = 'C:\Files\2c2b2541\00025\test.x'
>>> path
'C:\\Files\x02c2b2541\x0025\test.x'
>>>
>>> print(path)
C:\Filesc2b2541 25     est.x
>>>
>>> final_path = get_fixed_path(path)
>>> final_path
'C:\\Files\\002c2b2541\\00025\\test.x'
>>>
>>> print(final_path)
C:\Files\002c2b2541\00025\test.x
>>>

And here is the detailed description of each and every steps/statements in the above solution.

First step (problem) 
>>> import os
>>>
>>> path = 'C:\Files\2c2b2541\00025\test.x'
>>> path
'C:\\Files\x02c2b2541\x0025\test.x'
>>>
>>> print(path)
C:\Filesc2b2541 25     est.x
>>>
Second step (problem) 
>>> path2 = repr(path)
>>> path2
"'C:\\\\Files\\x02c2b2541\\x0025\\test.x'"
>>>
>>> print(path2)
'C:\\Files\x02c2b2541\x0025\test.x'
>>>
Third step (problem) 
>>> path3 = path2.replace("\\", "\\\\")
>>> path3
"'C:\\\\\\\\Files\\\\x02c2b2541\\\\x0025\\\\test.x'"
>>>
>>> print(path3)
'C:\\\\Files\\x02c2b2541\\x0025\\test.x'
>>>
>>> path3 = path3.replace("\\x", "\\\\0")
>>> path3
"'C:\\\\\\\\Files\\\\\\002c2b2541\\\\\\00025\\\\test.x'"
>>>
>>> print(path3)
'C:\\\\Files\\\002c2b2541\\\00025\\test.x'
>>>
Fourth step (problem) 
>>> os.path.abspath(path3)
"C:\\Users\\RISHIKESH\\'C:\\Files\\002c2b2541\\00025\\test.x'"
>>>
>>> os.path.abspath(path2)
"C:\\Users\\RISHIKESH\\'C:\\Files\\x02c2b2541\\x0025\\test.x'"
>>>
>>> os.path.abspath('k')
'C:\\Users\\RISHIKESH\\k'
>>>
>>> os.path.abspath(path3).split("'")
['C:\\Users\\RISHIKESH\\', 'C:\\Files\\002c2b2541\\00025\\test.x', '']
>>> os.path.abspath(path3).split("'")[1]
'C:\\Files\\002c2b2541\\00025\\test.x'
>>>
Final step (solution) 
>>> final_path = os.path.abspath(path3).split("'")[1]
>>>
>>> final_path
'C:\\Files\\002c2b2541\\00025\\test.x'
>>>
>>> print(final_path)
C:\Files\002c2b2541\00025\test.x
>>>

Upvotes: 1

Lê Tư Thành
Lê Tư Thành

Reputation: 1083

Replace "\" by "\\".

That's it.

Upvotes: 0

BernardL
BernardL

Reputation: 5464

You need to either use a raw string literal or double backslashes \\.

import os
path = r'C:\Files\2c2b2541\00025\test.x' #r before the string

print(os.path.abspath(path))

Upvotes: -1

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