Changing file path and need for raw?

Question

import os

cwd = os.getcwd()

print("Current working directory: {0}".format(cwd))

# Print the type of the returned object
print("os.getcwd() returns an object of type: {0}".format(type(cwd)))

os.chdir(r"C:\Users\ghph0\AppData\Local\Programs\Python\Python39\Bootcamp\PDFs")

# Print the current working directory
print("Current working directory: {0}".format(os.getcwd()))

Hi all, I was changing my file directory so I could access specific files and was then greeted with this error:

SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 2-3: truncated \UXXXXXXXX escape

From there I did some research and was told that converting the string to raw would fix the problem. My question is why do I convert it to raw and what does it do and why does it turn the file path into a red colour(not really important but never seen this before). Picture below:

https://i.stack.imgur.com/4oHlC.png

Many thanks to anyone that can help.

https://www.btelligent.com/en/blog/best-practice-working-with-paths-in-python-part-1/ — jak123, Nov 22 '21 at 20:12

Tim Roberts · Answer 1 · 2021-11-22T20:13:11.053

0

Backslashes in strings have a specific meaning in Python and are translated by the interpreter. You have surely already encountered "\n". Despite taking two letters to type, that is actually a one-character string meaning "newline". ANY backslashes in a string are interpreted that way. In your particular case, you used "\U", which is the way Python allows typing long Unicode values. "\U1F600", for example, is the grinning face emoji.

Because regular expressions often need to use backslashes for other uses, Python introduced the "raw" string. In a raw string, backslashes are not interpreted. So, r"\n" is a two-character string containing a backslash and an "n". This is NOT a newline.

Windows paths often use backslashes, so raw strings are convenient there. As it turns out, every Windows API will also accept forward slashes, so you can use those as well.

As for the colors, that probably means your editor doesn't know how to interpret raw strings.

edited Nov 22 '21 at 20:13

answered Nov 22 '21 at 20:10

Tim Roberts

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Thank you very much. This answered my question perfectly. As for the code coming up in red, is it meant to look like that? – abcdefg Nov 22 '21 at 20:13
That's an artifact of your editor, which we don't know. I'd call it a bug that it doesn't recognize raw strings. – Tim Roberts Nov 22 '21 at 20:13
Ok thanks. Is there a way to fix this? – abcdefg Nov 22 '21 at 20:16
You'll have to check with whatever editor you use. If it really bothers you, switch those all to forward slashes, Then you don't need the `r` at all. – Tim Roberts Nov 22 '21 at 20:17
Ok. Thank you for all your help :) – abcdefg Nov 22 '21 at 20:19

Changing file path and need for raw?

1 Answers1