SyntaxError when trying to use backslash for Windows file path
Question:
I tried to confirm if a file exists using the following line of code:
os.path.isfile()
But I noticed if back slash is used by copy&paste from Windows OS:
os.path.isfile("C:UsersxxxDesktopxxx")
I got a syntax error: (unicode error) etc etc etc.
When forward slash is used:
os.path.isfile("C:/Users/xxx/Desktop/xxx")
It worked.
Can I please ask why this happened? Even the answer is as simple as :”It is a convention.”
Answers:
You get the problem with the 2 character sequences x and U — which are python escape codes. They tell python to interpret the data that comes after them in a special way (The former inserts bytes and the latter unicode). You can get around it by using a “raw” string:
os.path.isfile(r"C:UsersxxxDesktopxxx")
or by using forward slashes (as, IIRC, windows will accept either one).
Backslash is the escape symbol. This should work:
os.path.isfile("C:\Users\xxx\Desktop\xxx")
This works because you escape the escape symbol, and Python passes it as this literal:
"C:UsersxxxDesktopxxx"
But it’s better practice and ensures cross-platform compatibility to collect your path segments (perhaps conditionally, based on the platform) like this and use os.path.join
path_segments = ['/', 'Users', 'xxx', 'Desktop', 'xxx']
os.path.isfile(os.path.join(*path_segments))
Should return True for your case.
Because backslashes are escapes in Python. Specifically, you get a Unicode error because the U escape means “Unicode character here; next 8 characters are a 32-bit hexadecimal codepoint.”
If you use a raw string, which treats backslashes as themselves, it should work:
os.path.isfile(r"C:UsersxxxDesktopxxx")
I tried to confirm if a file exists using the following line of code:
os.path.isfile()
But I noticed if back slash is used by copy&paste from Windows OS:
os.path.isfile("C:UsersxxxDesktopxxx")
I got a syntax error: (unicode error) etc etc etc.
When forward slash is used:
os.path.isfile("C:/Users/xxx/Desktop/xxx")
It worked.
Can I please ask why this happened? Even the answer is as simple as :”It is a convention.”
You get the problem with the 2 character sequences x and U — which are python escape codes. They tell python to interpret the data that comes after them in a special way (The former inserts bytes and the latter unicode). You can get around it by using a “raw” string:
os.path.isfile(r"C:UsersxxxDesktopxxx")
or by using forward slashes (as, IIRC, windows will accept either one).
Backslash is the escape symbol. This should work:
os.path.isfile("C:\Users\xxx\Desktop\xxx")
This works because you escape the escape symbol, and Python passes it as this literal:
"C:UsersxxxDesktopxxx"
But it’s better practice and ensures cross-platform compatibility to collect your path segments (perhaps conditionally, based on the platform) like this and use os.path.join
path_segments = ['/', 'Users', 'xxx', 'Desktop', 'xxx']
os.path.isfile(os.path.join(*path_segments))
Should return True for your case.
Because backslashes are escapes in Python. Specifically, you get a Unicode error because the U escape means “Unicode character here; next 8 characters are a 32-bit hexadecimal codepoint.”
If you use a raw string, which treats backslashes as themselves, it should work:
os.path.isfile(r"C:UsersxxxDesktopxxx")