If I have a string
dummy_path = "this is a dummy path\basic"
The \b character is of course a backspace, so this get printed (and processed by filesystem calls) as
this is a dummy patasic
(Patasic, nice name!)
Do I have a chance to detect this situation and warn the user (myself) that the \ in dummy_path should be, for example, either escaped or substituted with a /?
You can see for yourself:
>>> dummy_path = "this is a dummy path\basic"
>>> dummy_path
'this is a dummy path\x08asic'
The len function also reflects this:
>>> len("a\bc")
3
>>> "a\bc"
'a\x08c'
>>> print("a\bc")
c
as does the in operator with two strings as arguments:
>>> "\b" in "a\bc"
True
How it is displayed is entirely dependent on your output device. Most terminals will print each character one after the other. The \b, instead of being visible, simply repositions the cursor one position to the left, at which point the a overwrites the previously written h.
Notably, this is how a man page displays bold text. Man pages (which are on-screen renderings of *roff code) use letter-backspace-letter sequences to indicate a letter should be displayed in bold face. The metaphor comes from typewriters: to type a letter in bold, you type it once, backspace, then type it again over the first one. Similarly, underlining can be represented as letter-backspace-underscore.
repr (which is what my example, displaying the value in the interactive shell, demonstrates implicitly). dummy_path is a string value, while repr(dummy_path) returns a string that represents a string value, specifically with otherwise unprintable characters replaced with a \x?? representation.
if "\b" in dummy_path:in operator, when both arguments are strings, behaves a little bit differently; it returns True if the first argument is a substring of the second, rather than if the first argument is an element of the second.
print(repr(dummy_path))r"dummy\basic"will interpret the backslash as just a backslash.