CODEWITHSUNDEEP
pythonpython-3.xfile-iounicode
DavidBoyd
DavidBoyd

Reputation: 3

Unicode error when opening a file in Python 3

I have been having a horrible time just trying to open a file in python 3 because of the "\U" in the "C:\Users..." microsoft path name. I'm getting the error "SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes..."

I've read the other answers to this problem that offer the following solutions:

  1. Double the \ to escape the unicode of the "\U"

  2. Use a raw string filename = r"C:\Users.."

  3. Switch the \ to /.

Whenever I use option 1 and/or 2 it doubles the "\". So, the filepath is wrong because it reads 'C:\\Users\\..." instead of 'C:\Users\...'

I'm trying to open excel files at work to manipulate data, and so option 3 isn't available to me, as I can't change the filepath.

Can someone explain why the "\" are doubling when I use the escape "\" or a raw string?

I've tried every combination of options and can't seem to get this to work.

Sorry for making a new question to an already answered problem, but I couldn't comment on the other answers, and the accepted answers weren't working for me.

Thanks

Upvotes: 0

Views: 3537

Answers (2)

Andrew Hewitt
Andrew Hewitt

Reputation: 538

The original answers should work.

Option 1:

file_path = "c:\\User\\USER\\SOMETHINGELSE"
print(file_path);

gives:

c:\User\USER\SOMETHINGELSE

The slash escapes the character next to it, but doesn't print itself.

Option 2:

file_path = r"c:\User\USER\SOMETHINGELSE"
print(file_path);

gives:

c:\User\USER\SOMETHINGELSE

The r tells the string that it has to take it as literal and not use any escape characters.

Option 3:

OK...So if you really can't use options 1 or 2, you could use:

import os

file_path = os.path.join(os.path.abspath(os.sep), 'Users', 'USER', 'SOMETHINGELSE')
print(file_path);

In this case 'os.path.abspath(os.sep)' returns the root drive you are currently using. In my case C:\. 'os.path.join' concatenates the strings using the current systems delimiter. On windows this is \.

The result is:

C:\Users\USER\SOMETHINGELSE

But, that is a strange way of doing things when option 1 or 2 should work fine. Remember not to use the options together. If you combine options 1 and 2 you will not get the correct result. Use one or the other.

Upvotes: 2

Nick T
Nick T

Reputation: 26717

If you have a string with an escape character in it (\) and Python displays it's representation, it will appear to be doubled:

# in the REPL
path = r'C:\Users\Nick'

path 
# 'C:\\Users\\Nick'

print(path)
# C:\Users\Nick

print(repr(path))
# 'C:\\Users\\Nick'

You are likely being confused in the REPL by Python printing the representation of a string rather than what it actually contains.

Note that your choices 1 and 2 are identical:

'C:\\Users\\Nick' == r'C:\Users\Nick'
# True

Also note that if you enter an invalid escape (e.g. '\D'), Python will silently correct this for you to '\\D'. This will issue a DeprecationWarning in Python 3.6 and a SyntaxError at some point in the future.

Upvotes: 0

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